Friday, October 22, 2010

Jomari's Scribepost October 22, 2010

Dividing Decimals
To start out class, we multiplied a few numbers. One of the interesting questions was 0.1x100.

0.1x100 = 10 because 1x100=100 Once you find 100 you just put the decimal place in. This will help us when we do our division.
One more question is 0.1 x 1
0.1x1 = 0.1 Because anything multiplied by ONE will equal ITSELF

After doing these questions, we were told that anything divided by 0 is not zero but undefined.
We then went on to learn about dividing.

Here is the first question:

We were not allowed to use calculators so we did this the long way.
We first thought about what you do when you divide.
Dividend ÷ Divisor = Quotient To make this question easier, we need to change the divisor (2.5) into a whole number.
To change the divisor into a whole number, we need to multiply it by 10.
If we multiply the divisor by 10 then we need to multiply the dividend by 10.

2.5x10=25
1.265x10=12.65


Now we solve the question
To start, we have to find out how much times 25 fits into 12. It fits into twelve 0 times. so we put a zero on top. We also need to line up the decimals so we know that the answer is less than 1.

We then find out how much times 25 fits into 126 because it does not fit in 12.
It fits 5 times so we put that on top.
We multiply 25 by 5 to get 125 and we then subtract that. But we still need to line up the decimals.

How much times does 25 fit into 15? 0. Because of this we need to add a zero after the 5 at the answer and after the15. How many times does 25 fit into 150?6. So we add a 6 to our answer. We then multiply and subtract.
25x6=150




Because we end up with 0, we now have the answer, 0.506
We thought that we have to convert the answer because we changed the dividend and the divisor but we don't have to change the answer because
the changed numbers were equivalent to the original so dividing them would give you the same equivalent answer.
For Homework we had to do all the division questions in the yellow book.
Thanks for reading( if you actually did)! Please correct me and make suggestions on how to improve my post
For the next post I pick Josh? Alex. Fo' Sho

4 comments:

  1. Good job Jomari! In the question 0.1 x 100=10, when you were explaining about putting the decimal in it's place, you could've added that there is one decimal place. I think that would make things clearer. You did such a good job at explaining though. And it's really nice how you made a diagram/picture for each step of the long division. Keep up the good work!

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  2. You're font size is really big.

    I like how important stuff is coloured red.

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  3. Great job Jomari! Very understandable and well organized.

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  4. Good job Jomari! I like how you made things stand out by colouring them red. :D

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