## Thursday, September 30, 2010

### Kamille's Blog Post for September 30th

Today in math class, we went over the homework with the net of the diagram he drew for us yesterday. The net looks something like this:

Also we did a 3D diagram in an isometric dotted paper that looks something like this:

Then we did the went over one of the Show You Know on Page 29 on the math-book.

Question
: What is the area of the surface that is against the ground? Explain your answer.

S.A = 80( 60 + 20+ 30 + 20
)
S.A = 10,400 cm

S.A = 2 [40 (60) + 20 (30) ]
S.A = 2 ( 2400 + 600 )
S.A = 2 (3000)
S.A = 6000 cm

Then you add 10,400 + 6000 which equals 16,400 cm2.

HOMEWORK

- Finish Check Your Understanding question 2 and 3.
- Do the ALL the apply and practice.

REMEMBER DUE ON MONDAY.

AND FOR THE NEXT PERSON I PICK TO DO THE BLOG IS,........... MICHELLE. (: TEHE.

## Wednesday, September 29, 2010

### Argie's blog post!!!

Today in math class we started it off by doing a integer quiz thingy.
Today's integer assignment look a little something like this

BLACK - numbers were subtracting

Next, all we did was basically go over the TEST that we did the other day and see what errors people had, and how to fix them.

After that Mr.Backe showed us a few images and told us to find out what "x" and "y" are. This is the images he showed us...

To find "x" you would have to subtract 8 from 5. So the answer would be 3. You have to do that because you are trying to find the "x" and that is part of the height.
So it would be like..
x=8-5
x=3

To find "y" you have to subtract 5 from 3. The answer would be 2. You have to do this because you are finding out what "y".
And it looks lie this..
y=5-3
y=2

Yeah i guess that's pretty much it.

HOMEWORK!!!!
- syk
- cyu 2 & 3
Answer : Explain the difference between a oblique and a diagonal line.
OHHHHHH! and for that picture up there ^ you have to make the object in 3D and also a net!
And play tutpup!

Ohh and if your wondering why its so dull and plain, its because the colours i put on it wouldn't stay when i published it!

AND KAMILLE IS DOING THE NEXT BLOG
HAVE FUN KAMILLE ;)

## Tuesday, September 28, 2010

### EMMANUELS BLOG POST?!

In today's math class, we worked on calculating the area of prisms and cylinders. We also worked a bit on finding the volume of a prism.

To calculate the area of faces on a cylinder, you must use the formulas:
πr² (pi x radius squared) AND 2πrh (2 x pi x radius x height)

For finding the area of the top face of a cylinder you must use the formula:
πr²

For example:
The radius of the cylinder is 5cm

π r ²(pi x radius squared)

(3.14) (5²) I got 3.14 from pi, and 5 because that is the radius.

(3.14) (25) After squaring 5, you are left with 25.

After multiplying 3.14 and 25, the top face of a cylinder would be:
78.5cm²

You also need to know the formula for finding the area of the rectangle in a cylinder. The formula for that is:
2πrh (2 x pi x radius x height)

For example:
A cylinder has a radius of 4, and a height of 3.

2 π r h (2 x pi x radius x height)

2x(3.14) (4) (3) 3.14 represents pi, 4 is the radius, and 3 was the height

(6.28) (4) (3) I got 6.28 after multiplying 3.14 by 2

(25.12) (3) 25.12 was from multiplying 6.28 by 4

75.36cm² is the area of the rectangular face on a cylinder

For finding the surface area of a prism, you will need the following formula:
2(lxw)+ 2(lxh)+ 2(hxw)
(You add the two because there are 3 pairs of opposite sides with the same area)

For example:
A prism has a length of 5, a height of 2, and a width of 3, what is the surface area?

To start off, you would need the formula:
2(lxw)+ 2(lxh)+ 2(hxw)

Then replace the variables with their numbers:
2(5x3)+ 2(5x2)+ 2(2x3)

One at a time you multiply the brackets:
2(15)+ 2(10)+ 2(6)

Once you've done that, you multiply the lengths by 2:
30+20+12

62cm²

Now that were done.. just kidding we have to learn volume now.

To find the volume of a prism, you must use the formula:
WxDxH (width x depth x height)
(though they might not always give you the exact numbers)

For example:
A prism has a width of 2, a depth of 2, and a height of 2.

Start of with your fancy formula:
WxDxH

Fill in the numbers:
2x2x2

MULTIPLY:
8cm³(volume is always cubed)

Thank you for reading my scribe post which took 5 hours.

WANT MORE PRACTICE? VISIT THESE SITES www.shodor.org/interactive/activities/surfaceareaandvolume www.mathguide.com/lessons/SurfaceArea.html

PLAY MORE TUTPUP CHILDREN

I choose JERIC for the next scribe.. just kidding it's actually
ARGIE

## Friday, September 24, 2010

### Darnell's BLOG POST.

HELLO CLASS.

Today in class we learned about Surface Area of a CUBE and RECTANGULAR PRISM.

BEFORE all that, we learned how many lines of symmetry a 3 dimensional cube has.
There are a total of 9 lines of symmetry.
( Sorry if the picture seems a pretty trippy to you. )

Surface Area of a Cube
Cube - Has 6 faces
Congruent faces
Congruent means its the same shape and size.

Surface Area = 6s²
When calculating the surface area you must use the rule:
BEDMAS ( Brackets Exponents Division Multiplication Adding Subtracting )
6S = 6 Sides. A cube has 6 sides/faces.
An example of the variable S would be the number 3.
SA = 6s²
= 6(3)² ** The exponent ² means to square the number ( or multiply the number by itself ) **
= 6 x 9 ** The number we get it 9 because of 3 x 3 **
= 54 cm² or 54 squared centimeters.
Another example for the variable S would be 2.25
SA = 6s²
= 6(2.25)²
= 6 x 5.0625
= 30.375 cm² or 30.375 squared centimeters.

Next is calculating the Surface Area of a Rectangular.
6 faces of which there are 3 pairs of opposite congruent faces.
We didn't get far into calculating the surface area of a rectangular prism. This is how far we've got up to.

H O M E W O R K
1.3 WARM UP
INTEGER SHEETS
AND
TEST ON MONDAY

FOR THE NEXT PERSON TO DO THE BLOG I PICK:

EMAN

## Thursday, September 23, 2010

### Jerick's Math Blog Post !

HELLO FELLOW CLASSMATES
and Mr. Backe !

Today in math class the first thing we did was we were given a grid , an integer grid and we had to write numbers on the top and along the side and it was addition . It was a timed integer assignment. This is what the assignment looked like .

sorry if you can't really see the numbers . i tried my best .

Also in math , we talked about rotating an object around a point . Heres what it looks like

im sorry that its kind of hard to understand or see

Black Shape = Where we started
Black Line = Line of Reflection
Purple Shape= Where it ends when reflected
Red Shape = Where it ends once reflected and rotated around point J which is located on ( 0,-3)

Okay , this is a technique that i used ..

Lets start with reflection , say Point A . I counted diagonally to the Line Of Reflection and i got 2 and a half squares . So from the Line of Reflection , i counted diagonally 2 and a half sqaures . Thats what i did with all of the Points .

For the Rotation , i drew a 90 degree angle , as you can see it says 90 degrees in PURPLE . So i started with Point C' . i counted 2 spaces in between the Center of Rotation and Point C . For a 90 degree angle i counted up from the Center of Rotation two spaces . I did that for all Points as well .

Im sorry if you can't really understand my explanations , i make things difficult in my head so its really hard for me to explain how i get my answers .

HOMEWORK :

PLAY TUTPUP

INTEGER SHEETS ( DUE MONDAY )

STUDY FOR THE SYMMETRY TEST

FOLDABLES

PLUS THE WORK THAT HE ASSIGNED FROM THE BEGINNING

THANK YOU FOR TAKING SOME TIME TO READ THIS !
AND PLEASE GIVE ME SOME FEEDBACK
I CHOOSE Dee' LADEEZMAN - Darnell

## Tuesday, September 21, 2010

### September 21, 2010

HI CLASSMATES !

Today in math classed we learned about different ways we can rotate a figure on the coordinate grid !.

We learned 3 different methods that can help us rotate a figure on a coordinate grid.
Method # 1
The first method is we can grab any object with a right angle( e.g a piece of paper ). Then we line it up any letter that is part of the figure you're rotating. You can now rotate it how ever you want counter clock wise or clock wise.
Looks something like this :
Method # 2
The second method is rotating the object by first picking a letter part of your firgure like A. Then from the center of rotation count horizontal toward the firgure, then count vertical to the figure, then rotate that mini kind of object the way you need to. This is the way i use because its pretty easy.
Looks something like this : Method # 3
This is for if you really dont get it and you need to use a figure and a string. First you trace your figure on another paper then cut it out. You then attach a string to get then rotate it.
Looks something like this:

SORRY IF ITS HARD TO UNDERSTAND I TRYED MY BEST !

homework was Extend 24 and 25 (hard), Workbook 1.2, Extra Practice 1.2 if you missed it.

INTERGER TEST TOMMOROW. !!!!

## Monday, September 20, 2010

### September 20, 2010

Today in math we've learned about rotation symmetry.

Rotation symmetry just means how many times a polygon fits onto its self to complete one rotation.
For example:

This flower can fit 9 times to its self.

Then we had to find the angle of rotation. Since it has 9 rotation symmetry, we have to divide it by 360 degrees. The reason why its 360 degrees is because the polygon used on the example above is fully turned which makes 360 degrees.

We then drew rotations on our graphs. The rotation can be clockwise or counter clockwise.
For example:

I choose Alvin to do the next blog.