Sunday, November 28, 2010

Elaine's Scribe Post

Hey everybody! In class, we went over what was due on Monday. They were:

-the exponent foldable 1 (this foldable is the one Mr. Backe handed to us. It had the list of the different laws. Here, we write an explanation of the laws, give examples of it, and on the back you write three BEDMAS questions and answer it.)

-the exponent foldable 2 (this is the foldable that we folded into thirds and then into fifths. Here, we write the definition, examples, and not examples of POWER, EXPONENT, BASE, COEFFICIENT, and EXPONENTIAL FORM.)

- the self -assessment of chapter 3

-------------------------------------------------------------------------------------------------

Then, Mr. Backe wrote questions on the board for us to answer.They were:







































Tuesday, November 23, 2010

Camille's Scribepost

Today in math class we had to find the answer to say for example 8²= 64 the answer is 4 because we look for the number that is in the ones place and also find the pattern. We also had to figure out some math problems.


examples:
















Circle radius is 4 cm. How much of the square is not covered by the circle?
Formula: (2r)² -π r²
Answer:
(2r)² -π r²
(2•4)² -π 4²
8²-π 16
64-16.π
= 13.73 cm²
First do the bracket. r= 4. So 2 multiplied by 4 equals 8². then 4² = 16. 8² = 64. So 64 subtract by 16 multiplied by π. equals 13.73 cmπ



Side is 12 cm. How much of the square is not covered by the circle?
Formula: s² - π ( s/2) ²
Answer:
12²-π (12/2)²
12²-π 6²
144-π 36
= 30.90 cm²

S²=12². Then you do the brackets, so 12 divided by 2 all squared equals 6². 12² equals 144 and 6² equals 36. So 144- π x 36
We also learned what a coefficient is. It is the number you multpiy by. Like 4x, 4 is the coefficient and x is variable.
Oh remember to comment If I made any mistakes! Thank you!
by the way sorry for the layout. blogger isnt cooperating with me.



























Sunday, November 21, 2010

Jem's scribepost for november 19 2010

Oh Harro guys ! How was your weekend? Good okay. Anyways. . . As of last Wednesday to Friday we've been learning about "EXPONENTS". At the moment we should already know or have a better understanding on:
  1. the different exponent laws
  2. how to identify different exponents
  3. how to solve different exponent type questions
    REMINDER: The pictures aren't in their best qualities so just click on the images to get a better view of the work I'm showing you guys! Thanks!
Our lesson on Friday focused on the three other laws that we didn't cover on Thursday so stay tuned because here i am to tell you what has been going on, on Thursday. IF YOU WEREN'T IN CLASS THEN YOU BETTER READ THIS! or else. . . i don't know. I better get this started so here we go.

Power of a Product Law-
When a product is raised to a power, you can rewrite the product by applying the exponent to each factor. Which means you use the same power for both numbers.
(a x b)2 = a2 x b2


Power of a Quotient Law-
When a quotient is raised to an exponent, you can rewrite each number in the quotient with the same exponent. Which means rewrite the the same quotient as many times as the power tells you too.
(a÷b)³ = a³÷b³
(a/b) ³ = a³/b³


Negative Exponent Law-
One is the numerator and the denominator is the positive exponent with the same base. (*Honestly I'm still kind of confused about how this law works so, if i do something wrong just tell me. And Mr.backe I need help!)
a¯¹ = 1/a¹
a-² = 1/a²


Okay, guys. . Thanks for spending your time to look at my blog post. Feel free to comment on how well/poorly my post was. Don't be afraid to make some suggestions on how I can make this blog more better. *DON'T FORGET TO DO YOUR HOMEWORK OR BACKE WILL BLOW IT :)*
  • Stash it :All tests signed
    Self Evaluation
    Problem of The Week 3 and 4
    Foldable (divide/add/subtract/ multiply fractions and decimals), Different groups of Numbers
  • Do your Journals
  • Textbook and homework book questions
  • Study all the time
  • Comment at blogs
    Enjoy the 4 hours you have left of your week end. Okay okay ? Okay cool. Bye guys :)
CAMILLE CONCEPCION, your up next !

Thursday, November 18, 2010

Seppe's scribe post for November 18th

Today in class, we moved to the next chapter. Mr. Backe taught us power and exponents.


A power is a quick way of writing repeated same number multiplication.

Base is the number used as a factor for repeated multiplication.
Exponent is the number of times you multiply the base in a power by itself.

22 = two squared = (lh) = 2x2
23 = two cubed = (lhw) = 2x2x2

You could also say -two to the exponent of 2 or 3
-two to the second/third power

Ordinality describes position. eg. 1st, 2nd, 3rd.....

Here are some examples of how you do it....

24= 2x2x2x2 = 16
23= 2x2x2 = 8
22= 2x2 = 4
21= 2 = 2
20= 1

34= 3x3x3x3 = 81
33= 3x3x3 = 27
32= 3x3 = 9
31= 3 = 3
30= 1

Laws

Zero Exponent Law- any base to the exponent of zero is 1. (X0=1)
Exponent Law of One
- any base the exponent of 1 is itself. (X1=X)
Product Law- any powers with the same base when multiplied, add the exponents to get the new power. (73 x 75 = 78), (122 x 123 x 124 x 12=1210), or (am x an=am+n)

***Be careful when adding the exponents. Always remember that a number without an exponent (12) has a hidden one (1)

Quotient Law- when any powers with the same base are divided, subtract the exponents to get the new power. (44 / 42 = 42), (57 / 53 = 54), (am / an = am-n)

Power of a Power Law- when one (1) is raised to any exponent, it will always equal 1.

Power of a Power Law example...
14= 1x1x1x1 = 1
13= 1x1x1 = 1
12= 1x1 = 1
11= 1 = 1
10= 1

Here's a little video for you to watch :)

Wednesday, November 17, 2010

Question 12

12. In the table, a positive number shows how many hours the time location in ahead of the time in London, England. A negative number shows how many hours the time is behind the time in London.


*First of all: remember that in adding and subtracting fractions, you must find a common denominator first (if needed).

a) How many hours is the time in St. John's ahead of the time in Brandon?

To find the answer, I subtracted the amount of time in Brandon from the amount of
time in St. Johns. A diagram below shows you how I solved it, and therefore the time in St. John's is 2 and 1/2 hours ahead of the time in Brandon.


b) How many hours is the time in Victoria behind the time in Mumbai?
The process in the same as the last question, I subtracted the time in Victoria from the one in Mumbai. Below, it shows that time in Victoria is 13 and a half hours behind from that of Mumbai.


c) Determine and interpret the time difference between Tokyo and Kathmandu.
Once again, I subtracted the two times of both places. The diagram below shows that Tokyo is 3 and 1/4 hours ahead of Kathmandu.

d) Determine and interpret the time difference between Chatham Islands and St. John's.
I subtracted the amount of time in Chatham Islands to that of St. John's. The diagram below will show that Chatham Islands is 16 and 1/4 hours ahead.


e) In which location is the time exactly halfway between the times in Istanbul and Alice Springs?
The time in Kathmandu, Nepal is halfway between times in the other two locations. How did I know that? Because I added the times in Istanbul and Alice Springs (refer to chart above) and then I divided their sum by 2 because we are finding the halfway point. (Half= 2)

Thank you for reading :)

Monday, November 15, 2010

Seppe's scribepost

Question 18, 2.4 on page 79

18. A frame measures 30 cm by 20 cm. Can you mount a square picture with an area of 500 squared cm in the frame? Explain.

Frame
= 30 x 20

Picture
= 500

So to find the sides of the picture, you have to find the square root of 500 which is 22.36.
One side of the picture is too big for the frame so the answer is no, it can't fit in the frame.

PLEASE COMMENT (IF YOU WANT) TO MAKE MY POST A BETTER ONE :D

Sunday, November 14, 2010

Connor's Post for November 9th Question 13

In math class we were all assigned questions and mine was question 13 in section 2.3.

13. The diameter of Pluto is 6/17 the diameter of Mars. Mars is 17/300 the diameter of Saturn.

A) What fraction of the diameter of Saturn is the diameter of Pluto.

Since Pluto is 6/17 of Mars and Mars is 17/300 of Saturn you need to cancel out the 17.
You are left with 6/300 and that is 0.02.
0.02 x 50 = 1
1/50 is the final answer.

B) The diameter of Saturn is 120 000 km. What is the diameter of Pluto?

1/50 = 0.02
120000 x 0.02 = 2400
The diameter of Pluto is 2400km.

Question 17 2.4 by The Most Awesomest Alex

Yeah yeah awesomest isn't a word I know but still, I'm awesome so I put that, but anyways to the question, I would've done this sooner but my dad needed to use his computer for work or something so I waited but he's done so I can use it.

Basic things really you just need to know how to find area the steps at least, and how to multiply simple.

17. Some parks contain fenced gardens. Suppose that it costs $80 to build each metre of fence, including materials and labour.

A) How much does it cost to enclose a square with an area of 120 squared metres? Express your answer to the nearest dollar.

Well first of all you have to isolate how many metres are in each side of the fence, you do that by square rooting(?) the area to get a side length, you should get about 10.95 then you have to multiply that by 4 because of each side so it equals, 43.816. Haha I last step multiply that by 80 because you need to find out the price of the work and materials put in so 43.816x80=3505.28 but you need to round it to the nearest tenth so it's 3505.3.
It will cost $3505.30 to enclose the area.

B) Predict whether the total cost of enclosing two squares with an area of 60 squared metres each is the same as your answer to part a).

Well I think it wouldn't because even if the 2 squares shared a fence you would still need to add that to the total amount of fence needed, because everything else would be similar if not the same (it's a guess).

C) Test your prediction from part b) and describe your findings.

Gah more math, and I thought we were supposed to be lazy, geez.
Well anyways same process as A) so 60 squared metres square rooted(?) is 7.746 that multiplied by 4 is 30.984. Multiply 30.984 by 2 because there is 2 squares and you get 61.968, now there's 2 ways of going from here assume they don't share a fence, and assume the do, for the sake of having all the proof, I'm doing both, your welcome.
61.968x80=4957.44 (4957.4 rounded)
61.968-7.746(once side of fence)=54.222
54.222x80=4337.76 (4337.8 rounded)
So it would either cost $4957.40 or $4337.80 which means I was correct for the main part of my prediction was correct in saying it would cost more.

There FINISH HA done.
Any questions just comment.
Again no colour sorry I'm just really lazy.

Jerick's Math Blog Post for 2.3 , November 14, 2010

Hey everyone ! This is my blog post for the question I was assigned for math
the question is ..

24. Can the sum of two rational numbers be less than both of the rational numbers? Explain using examples in fraction form .

The answer would be, yes the sum of two rational numbers can be less than both of the rational numbers, that is ,if the sum is negative.

Example:
(-3/4) + (-2/3 ) = -17/12 or -1 5/12

I have to admit, this question kind of confused me, so please, if anyone can explain it to me, I would gladly appreciate it
and
If you have any other examples, please feel free to put it as a comment
Thank You for Reading My Post

Mary Jane's Scribepost for November 9, 2010

For today's math class, Mr. Backe assigned each of us a question to do for a scribe post. I was chosen to do number 22 of chapter 2.4 on page 80.


The hypotenuse of an isosceles right triangle has a length of 20 cm. What is the length of each leg of the triangle? Provide your answer to the nearest tenth of a centimetre.

Isosceles Right Triangle: a triangle with two equal side lengths.




Conclusion:


The triangle had a hypotenuse of 20 cm and so what I did was I used the formula c (squared) = a (squared) + a (squared) to get the length of a. Then I took 20 (squared) or 400 and divided it by 2 to get a (squared) by itself. So now we're left with square root of 200 = the square root of a (squared) to get a by itself. We then end up with 14.1 cm (rounded to the nearest tenths place) as the length of a.




Thanks for reading my scribe post. Please feel free to tell me what I did wrong and correct me when you are commenting.

Question 15

Hey its me Alex, I finally get to do my posts because I got my Internet security back on my computer.
This question wasn't to hard just basic multiplication of decimals.
Now on to the question.

15) In dry air, the temperature decreases by about 0.65 degrees Celsius for each 100-m increase in altitude.

A)The temperature in Red Deer, Alberta, is 10 degrees Celsius. What is the temperature outside an aircraft 2.8 km above the city?

Okay to solve this all you really need to do is multiply 0.65 by 28 because in 2.8km there is 28 groups of 100m.
o.65x28= 18.2
Then you subtract 18.2 from 10 to get -8.2
So the temperature outside the aircraft is -8.2 degrees Celsius.

B) The temperature outside and aircraft 1600m above Red Deer is -8.5 degrees Celsius. What is the temperature in the city below?

This is basically the same process just reversed instead of subtracting you add, so 0.65x16=10.4
then you add 10.4 to -8.2 to get 2.2.
The temperature in Red Deer is 2.2 degrees Celsius.

Well as a famous pig said Thats all Folks.
Comment if you don't get what I did.
The reason I don't have colour is for the people who know me, I'm lazy end of story.

Question 15

Jomari's Post November 14,2010

Question 21: Calculate the Following
A. 1/3(2/5 - 1/2) + 3/10
B. 3/4÷5/8 - 3/8 ÷ 1/2
C. 1 1/2 + 1 1/2 (-2 2/6 + 1/3)


A.)
1/3(2/5 - 1/2) + 3/10
1/3(4/10-5/10) + 3/10
1/3(-1/10) + 3/10
-1/30 + 3/10
-1/30 + 9/30
8/30
4/15

B.)
3/4÷5/8 - 3/8 ÷ 1/2
6/5 - 3/4
24/20-15/20
9/20

C.)
1 1/2 + 1 1/2 (-2 2/6 + 1/3)
1 1/2 + 1 1/2 (-2)
1 1/2 + -3
-2 1/2

When we do these questions, we just remember BEDMAS to do everything in order.
Please comment and tell me how to improve my post.

QUESTION 1 & 2

In math class, we were all assigned a question to do on the blog. I got two questions, 1 and 2, which are on the history link on page 71.

First off, this history link is about UNIT FRACTIONS. A unit fraction, is a fraction that always has a numerator of 1. If you are trying to show a fraction that has a numerator that is larger than 1, you have to express it by adding separate unit fractions.


Questions:

1. Express each of the following as the sum of two unit fractions.
2. Describe any strategies that helped you to complete #1.



















April's Scribepost

Once again, the whole class was assigned a question from the textbook. My question was from 2.3, page 68, #5.


5) Estimate and Calculate




Thank you for reading my post. Please leave a comment. :)

Question 10

Hola!!!

A carpenter has 64 m of baseboard. He installs 1/2 of the baseboard in one room. He installs another 3/5 of the ORIGINAL amount of baseboard in another room. How much baseboard does he have LEFT? -It's always good to highlight or acknowledge the KEY PARTS of a question.

This is how I figured it out:

Step one) 1/2

First, I took away one half of the baseboard from the original amount which is 64 m. One half of 64 is 32. So now, the carpenter is left with 32 m of baseboard.

Step two) 3/5

Now, the carpenter figures that he can use 3/5 of the original amount to cover another room. I honestly don't know how he got the job. Here's why:

1. He has already used 1/2 of the baseboard in one room
2. 3/5 is LARGER than 1/2

See my point? That said, I still need an answer so let's keep going.

3/5 of 64 is 38.4

I figured that out by dividing 64 by 5 and multiplying the quotient by 3.

Step 3) add

Finally, I added the two amounts together. (1/2 + 3/5)

32 + 38.4 = 70.4

70.4 - 64 = 6.4- I subtracted the answer from the original in order to find the difference which is the final answer.

THE CARPENTER IS SHORT 6.4 m OF BASEBOARD.

REMEMBER!!!...Always include a sentence answer if it is a word problem.

Thanks for reading I hope this made sense please comment thanks! :D

-LauraKathleen905

Question 22

Taj has three scoops for measuring flour. The largest scoop holds 2 1/2 times as much as the smallest one. The middle scoop holds 1 3/4 times as much as the smallest one.

Describe two different ways in which Taj could measure each of the following quantities. He can use full scoops only.

a) 3 1/4 times as much as the smallest scoop holds.

First off, i figured that the smallest scoop is 1, or 1/1.

To get 3 1/4 as much as the smallest scoop, I changed the fractions into decimals, so i ended up with

large scoop:2.5

medium scoop:1.75

small scoop:1.0

I then changed 3 1/4 to a decimal and got 3.25.

The two answers I came up with were:

1.large scoop (2.5) + medium scoop (1.75) - small scoop (1.0) = 3.25

2.two large scoops (5) - medium scoop (1.75) = 3.25

b)1/2 as much as the smallest scoop holds.

1.two large scoops (5) - two medium scoops (3.5) - one small scoop (1.0) = 0.5

2.two medium scoops (3.5) - three small scoops (3) = 0.5

if u have ne suggestions plz comment

Question 16

"Bella is more comfortable working with integers than with positive and negative decimal numbers. This is her way of understanding -4.3 + 2.5"

"-4.3 is -43/10 or -43 tenths.

25 is 25/10 or 25 tenths.

-43 tenths + 25 tenths is -18 tenths.

-18 tenths is -18/10 or -1.8.

So, -4.3 +2.5=1.8"

a) Use Bella's method to determine 6.1 + (-3.9)

6.1 is 61/10 or 61 tenths.

-3.9 is -3.9/10 or -39 tenths.

61 tenths + -39 tenths is 22 tenths

22 tenths is 22/10 or 2.2

Therefore, 6.1 + (-3.9) = 2.2

b) How could you modify Bella's method to determine 1.25 - 3.46?

You could multiply the decimal number by 10, 100, 1000... to make it into a whole number. Once you have found the difference/sum of the equation, then you could divide the difference/sum by 10, 100, 1000... to get it back into the right decimal place.

eg. 1.25 - 3.46

1.25x100=125

3.46x100=346

125-346=-221

-221/100=-2.21

Therefore, 1.25-3.46= -2.21

Kamille's Scribepost

HELLO, This is kind of late but anyway.. but we we're assigned a question to do and i had to do question 19 so let's get right to it.

QUESTION 19.












a) - 5 /4 b) 11/10 c) 16/13 d) - 3/2

Saturday, November 13, 2010

Elijah's ScribePost for November 13, 2010

For Math, my question was number 17, Chapter 2.3

17. To calculate -3/4 + (-2/3), Amy decided to convert the fractions to decimals and add the decimals on a scientific calculator.

a) Explain why she had difficulty in determining the exact answer by this method.
For Amy's method, she wanted to turn - 3/4 and -2/3 into decimals and just add them up.

If you convert - 3/4 into a decimal it would be - 0.75.


If you convert - 2/3 into a decimal it would be -0.6 repeating.

If you add those two up you can't get the exact answer because there is a repeating decimal in the question.

b) How should she calculate to get an exact answer?

Amy should just stick with adding it the fractions method.

- 3/4 + (-2/3)=

Well first you have to find the common denominator for the fraction. Their common denominator is 12. And how do you turn the denominator ( 4 ) and ( 3) to 12 ? You multiply 4 by 3 and you multiply the 3 by 4. Now the fractions denominator is 12. But you also have to do the same to both fractions numerator. So you multiply the 3 by 3 which is 9 and multiply the 2 by 4 which is 8. The fractions are now -9/12 and -8/12. Then you just add the 9 and 8 together and which becomes the numerator and the denominator stays the same.

Jennifer's Blog Post for November 9th

Hello everyone!

I'm sorry it's a late but, it's better than nothing right? Anyways, our class was assigned to a question to do for the blog on section 2.3. I was assigned to question 9.

Lori owed her mother $39. Lori paid back 1/3 of this debt and then paid back 1/4 of the remaining debt. How much does Lori still owe her mother?

The first thing I did was finding out how much did Lori paid back her mom the first time. What I did was that I divided the amount of money Lori owed her mother by 3. Which equals 13.

From there, now I know how much Lori paid her mother the first time, I needed to figure out the 1/3 part. I found out by subtracting 39 by 13. Which leaves 26 dollars left that Lori still owes her mother.

Now, I have to find out the amount of money Lori paid her mother the second time. So far, all I know is that Lori owes her mother 26 dollars left. And Lori paid 1/4 of that back. I need to find out the 1/4 of 26. I did that by dividing 26 by 4. Gives me 6.5 left.

Then, I subtract 26 by 6.5. Equals 19.5. In money form it would be $19.50

So, the answer to this question would be, Lori still owes her mother $19.50

That concludes my blog post. Thanks for reading! Please make any comments if I've made some mistakes! Thank you!


Friday, November 12, 2010

Brianna's ScribePost

Heeeey Sorry this is a little late but better late then never but anyways let's get into the fun world of math....

24. Give an example of a fraction in lowest terms that satisfies the following conditions.

a) greater than 0, with the denominator greater than the numerator
1/2 would be an example of a fraction greater than 0 because as a decimal it is 0.5

b) between 0 and -1, with the denominator less than the numerator
3/-5 as a decimal would be -0.6 which is between 0 and -1.

c) less than -2, with the numerator less than the denominator
-4/5 as a decimal would be -0.8 which is less than -2.

d) between -1.2 and -1.3, with the numerator greater than the denominator
6/-4 as a decimal is -1.5 which is between -1.2 and -1.3.


well that's all for now.

Please comment :)

Thursday, November 11, 2010

Sharmaine's Scribe Post for Novermber 12, 2010

Hi everyone! In math class we were assigned to do question in the textbook. I was assigned to do question 25 on page 70.

The question was:

The following expression has a value of 1
[- 1/2 + (- 1/2)] / [-1/2 + (-1/2)]

Use - 1/2 four times to write expressions with each of the following values.

a) -1 b) 0
c)1/4 d) 4
e) - 3/4 f) -1 1/2

What i did to figure out if my answer was correct i simply changed -1/2 in a decimal which would be -0.5.

a) [-1/2 + (- 1/2)] + [-1/2 - (-1/2)] = 1

-0.5 + -0.5 = -1
-0.5 - -0.5=0
-1 + 0 = -1

b) [-1/2 - (-1/2)] - [-1/2-(-1/2)]= 0

-0.5 - -0.5 =0
-0.5 - -0.5=0
0-0=0

c)[-1/2 x (-1/2)] - [-1/2 - (-1/2)]= -1

-0.5 x -0.5 = 0.25
-0.5 - -0.5 = 0
0.25 - 0 = 0.25
but in fraction form it would be 1/4


d) (-1/2) / (-1/2) / (-1/2) / (-1/2)= 4

-0.5 / -0.5 / -0.5 / -0.5 = 4
-0.5 / -0.5 = 1
1 / -0.5 = -2
-2/ -0/5 = 4

e) [-1/2 + (-1/2)] + [-1/2 x (-1/2)]= -3/4


-0.5 + -0.5 = -1
-0.5 x -0.5 = 0.25 or 1.4
-1 + 0.25 = -0.75 or -3/4


f) (-1/2) / (-1/2) / (-1/2) - (-1/2) = -1 1/2

-0.5 / -0.5 / -0.5 - -0.5 = -1.5 or -3/2 or -1 1/2
-0.5 / -0.5 = 1
1 / -0.5 = -2
-2 - -0.5 = -1.5 or -3/2 0r - 1 1/2

PLEASE COMMENT AND CORRECT ME IF I HAD ANY MISTAKES

Another Blog Post from Brendan

Hello,

We were assigned textbook questions from Chapter 2.3 and 2.4.
The question that I will be telling you about is question15 from chapter 2.4 on page 79.

The question is "Kai needs to replace the strip of laminate that is glued to the vertical faces on a square tabletop. The tabletop has an area of 1.69 squared metres. What is the length of laminate does she need?"

I solved this question easily by finding the square root of 1.69 squared metres.
Since the tabletop is square, finding the square root would be perfect.
Why, you may ask. Well, to get rid of the "squared" part and the square root of 1.69 is 1.3.

1.3 x 1.3 = 1.69

Kai needs a laminate with the length of 1.3 to replace the old laminate.

Sorry there are no pictures or colour. It still will not let me.

Thank You.

Jamie's Blog Post for November 9, 2010

Well hello everyone! I was told to do question 7 on page 68 on 2.3..... So I did. Hehehheh.

To divide fractions, I put them into the fractions from as shown. Then, I multiplied both fractions with the reciprocal of the denominator, so then I could get the denominator to be 1. And as we all know, if we divide a number by 1, it will still be that number.

In this question, there was no operation sign if that's what you call it, but I noticed that it was "kissing". So that means both fractions are multiplying.

The answer is negative, because if you multiply the numerators, you're also multiplying a negative number with a positive number.

The reciprocal I used in this question was -5/4.

To answer this question, I converted the mixed fraction into an improper fraction instead, so that I can multiply the fractions easier by multiplying the numerator with the numerator, and the denominator with the denominator.

I made a mistake in the equation, it's not multiplying, it's actually dividing. Sorry, my mistake. Hehehehhh.

THANKS FOR READING MY BLOG POST AND PLEASE LEAVE A COMMENT!
PS. Sorry if colours don't work.... Again.

Wednesday, November 10, 2010

Brianna's ScribePost

Heeeey everybody :)





11. In everyday speech, in a jiffy means in a very short time. In science, a specific value sometimes assigned to a jiffy is 1/100 s.

Naima can type at 50 words/min. On average, how many jiffies does she take to type each word?






Now this is how you solve it.





Well there are 60 seconds in a minute.



So 60 goes over 50 (60/50) and then you divide by 1o to get 6/5 then you multiply that by 1/100.



Then you multiply both numbers by the reciprocal 100/1 to get 600/5.



Then you simplify to get 120/1.



Therefore Naima types 50 words per every 120 jiffies.



Tuesday, November 9, 2010

Darnell's 2 IN 1 BLOG POST ?!

HELLO CLASS.
I'm going to put in a blog post that i was suppose to do into this blog post!
So it makes 2 blog posts in 1! I think..

Here we go.
First question.
# 27 The mean of 6 rational numbers is -4.3
a) What is the sum of the ration numbers?
-4.3
x 6 numbers
--------------------
- 25.8

b) If five numbers equal -4.5 what is the sixth number?
-4.5
x 5 numbers
--------------------
-22.5

So to equal -25.8 you must subtract -25.8 by -22.5 .
The answer you get is -3.3
To know its correct add -22.5 and -3.3 and you get -25.8

Second question.
a) The label on a 1-L can of paint states that the paint will cover an area of 10m2.
What is the side length of the largest area that the paint will cover.
Express your answer to the nearest hundredth.

So what you do here is try to find the side length of the largest area that the paint will cover.
A square will represent an area of 10m2.
To find the side length you find the square root of 10.
√10 = 3.16m

b) What is the side length of the largest square area that a 3.79-L can of the same paint will cover? Express your answer to the nearest hundredth of a meter.

What you do here is create a T chart. This will help from how big the can of paint
will cover.
A reason why you multiply by 3.79 is because of how big the can is which is 3.79L.

The answer you get for how big the can of paint can cover is 37.9m2.

Next you square root the number
√37.9 = 6.16m

Michelle's Scribepost for November 9,2010

Hey everyone! Today in class we were given questions from the textbook. I had to do question 6 from 2.3.

First you find the common denominator. Sometimes when you multiply both denominators you can find the common denominator, but that doesn't always work because you want the least common denominator. For example, in questions b), d), and e) If you multiplied both the denominators, the denominator would be a big number. So you have to find the least common multiple.

The next step is, whatever you do to the bottom (denominator), you do to the top (numerator).

*Refer to a) Think how many times does 3 go into 12? 4 times, so you have to multiply both the numerator and denominator by 4. (2 x 4 = 8) Also with the other fraction (3/4), you find how many times does 4 go into 12? 3 times, so you multiply the denominator and numerator by 3.

Then after you changed the fractions which are now equivalent fractions, (still referring to a) you minus (or add, depending on the question) the numerators. (8-9= -1) and keep the denominator the same.

In question e) there are mixed fractions. One way to change mixed fractions into improper fractions is by, multiplying the denominator by the whole number and adding the numerator to get the NEW numerator. Keep the denominator the same.

In question f) you can just take the whole numbers and fractions and separate them. First you do the whole numbers 1 + (-1) = 0. Then you do the fractions like you would normally do it.




Sorry if this doesn't really make sense, I tried to explain it. And sorry for lack of colours, it doesn't work.

Noelle Cuvos' Second Awesome Blog Post

So this is whats up, we all had to do a question from 2.3 and show our answers on the blog. So i had question number 4 from the History Link section from page 71.

4. Express each of the following as the sum of three unit fractions without using any fraction more than once.

a) 7/8 = 1/2 + 1/4 + 1/8
1/2 = 4/8
1/4 = 2/8
1/8 = 1/8
7/8

b) 11/24 = 1/4 + 1/8 + 1/12
1/4 = 6/24
1/8 = 3/24
1/12= 2/24
11/24

c) 3/4 = ?

Well for letter C, I couldn't find an answer after a while thinking about it. So comment and tell me what you got and how you got it, Thanks. peace !

Alvin's Blog Post Novemeber 9, 2010

Hello Fellow Classmates,

Today in class we were all assigned questions from the textbook. I was assigned question 19 on pg 79.

19. A square picture with an area of 100cm is mounted on a square piece of matting. The matting has 2.5 times the area of the picture. If the picture is centered on the matting what width of the matting is visible around the outside of the picture ? Give your answer to the nearest tenth of a centimeter.

First of all if the matting is 2.5 times the size of the picture, then the picture would be 250 cm ( 2.5 x 100 ). Then the picture is placed in the center of the matting so then we take away the area of the picture from the matting, so its ( 250 - 100 = 150). So now the area of the matting is 150cm, so now we have to find the width of the matting. First the sides of the pictures are 10cm because the area of the picture is 100 ( 10x10 = 100). The lengths of the sides of the matting is 12.2 since 150 squared is 12.24744871 ( I just rounded it ). So now since there is 2 sides on the picture since its placed in the middle the width of one side would be 1.1cm because (12.2 - 10 divided by 2) since there is two widths.

I tried my best to explain this and I'm sorry if you don't understand ):
(it's plain since my colour wont work

Princess' scribepost for November 9, 2010

HI GUYS!

So today we we're assigned a question from the textbook again and I was assigned, to do #16. If I did anything wrong please tell me. Also, if you don't understand the way I explained it, just tell me and I'll be glad to help you (:

16) Boris has 2 1/2 times as much cash as Anna.
Charlie has 3/4 as much cash as Anna.
Anna has $25.60 in cash.

a) How much cash do the three people have altogether?
Boris: Since he has 2 1/2 times as much as Anna, I'm gonna find what half of $25.60 is, then add with whatever 2 x $25.60 is. I;m multiplying by because 25.60 equals to 1 in this case, so if I multiply that by 2, I would get 2. Then half of 25.60 equals to 1/2 and if I add them together, it would equal to 2 1/2.

$25.60 x 2 = $51.20
$25.60 ÷ 2 = $12.80

$51.20 + $12.80 = $64.00

Boris has $64.00

Charlie: Since Charlie has 3/4 times as much as Anna, I'm gonna find what three quarters of $25.60 is by dividing it by 4, then multiplying the answer to that by 3. I'm dividing by 4 because i want to know what one quarter of 25.60 is. Then when I have 1/4 of 25.60, I can multiply that by 3, to get 3/4.

$25.60 ÷ 4 = $6.40
$6.40 x 3 = $19.20

Charlie has $19.20

$25.60 + $64 + $19.20 = $108.80

The three people had $108.80, altogether

b)How much more cash does Boris have than Charlie?
Well since Boris has $64, and Charlie has $19.20, all you have to do is subtract 19.20 from 64.

$64 - $19.20 = $44.80

Boris has $44.80 more cash than Charlie.

COMMENT and tell me if I got anything wrong or if you don't understand.
Oh, and I'm sorry if it's really plain, I still don't know why my colours wont show up ):

Hannah's blogpost

Hi guys!
So all my answers and everything, I just put them in images to make it easier, I guess. I know it's late but that is because I was having trouble at first trying to figure out how to get to the answers. I tried my best to explain how I got the answers. If I did anything wrong, tell me :) That's all








Jeric's Scribepost

Hello boys and girls.

Today in class Mr.Backe gave us some math question from the text book that we were assigned to do. I got a question from pg. 71 question 3 in the history section.

My question was ...

Q. Express each of the following as the sums of two unit fractions without using any fractions more than once.

a) 2/7 = 2/20 + 2/11

b) 2/9 = 2/16 + 2/20

c) 2/11 = 2/20 + 2/25

So first I am going to start with a.

A) So from what i think we have to do is just to add fractions that equal 2/7. So what i did was i converted 2/7 to a decimal so i could find out the value of 2/7. (100 ÷ 7) x 2 = 28.57. So from there i just experimented with random fractions and i came up with 2/20 + 2/11. 2/20 in decimal form is 10 and 2/11 in decimal form is 18.18. so when i added it up i got 10 + 18.18 = 28.18 which is close to 2/7 or 28.57.

B) So just like the a. i found the decimal value of 2/9 which is 22.22. So then once again i experimented and tried finding fractions that would equal close to 22.22. What i came up with is 2/16 + 2/20. (100 ÷ 16) 2 = 12.5 . (100 ÷ 20) 2 = 10. So then once again i added 12.5 + 10 = 22.5 which is pretty close to 22.22.

C) So just like the past 2 question i just repeated and found the decimal form of the fraction 2/11. 2/11 in decimal form is 18.18 so I experimented on different fractions and came up with 2/20 + 2/25. (100÷20) 2 = 10 . (100 ÷ 25) 2 = 8. So then once again i added the two up and got 10 + 8 = 18 which is pretty close to 18.18.

I'm pretty sure this is wrong but i tried and i hope at least i got the right idea.
COMMENT !!! :D
Aight pce guys.

Finish 2.3 and Start 2.4 !!!

Allysa's scribepost for November 9, 2010

Once again, we were assigned a question from the textbook on 2.3. I'm blogging on question eight.

8. a) -3/4 x (-1/9) =




b) 4/3 divided by 5/4 =
Inside the red circle, is the reciprocal of 5/4. I did this to make the denominator equal one.






c) -3/8 divided by 7/10 =



d) -17/8 divided by 5/4 =











e) 7/9 x (-6/11) =






f) -3/2 divided by -5/2 =













**Sorry the letters are scattered. They're on the right rows, they just moved to the right.**
Thanks for reading my blog, I hope you enjoyed it! But please comment before you go, it means a lot! (: