## Wednesday, October 12, 2011

### Irena's Proportion Post

Ratio:
A comparison of two quantities measured in different units (ex. 5:6, 5/6)
• Two term ratio: compare two quantities measured in the same units (ex. 2/3)
• Three term ratio: compares three quantities measured in the same units (ex. 2:3:4)
• Part to part ratio: compares different parts of a group to each other (ex. 2 balloons in a drawer to 3 balloons in a drawer)
• Part to whole ratio: compares on part of a group o the whole group (ex. If you have 10 balloons all together in a drawer and 4 was blue and 6 was green. Your part to whole ratio could be 4 blue balloon to 10 balloons all together.)
Rate:
A comparison of two quantities measured in different units.
(ex. 45km in 3 h)
Proportion:
An equation which states that two ratios or fractions are equal.
(ex. \$6/ 4 pencils = \$15/ 10 pencils)

1. 5 hours to travel 360 miles is about ____ mph

2. As a playgroup worker, if I increase the amount of apple juice I am serving at the playgroup from 25 ml to 100ml, how much should I increase the orange juice to keep the quantities in the same proportion?

3. What are the three ways you can prove that equivalent ration statements are true?

1. The first way you can prove that these ratios are equivalent is to divide the numerator by the denominator. When I divided 3 by 4 I got 0.75. Then I divided 12 by 16 and I got 0.75. That's how you know that they are equivalent. (Vertical)

2. The second way to prove that these ratios are equivalent is to divide the numerator by the numerator. So for this question, I divided 3 by 12 and got 0.25. Then I divided 4 by 16 and got 0.25. That is how you know if the ratios are equivalent or not. (Horizontal)

3. The third way to prove the ratios are equivalent is to multiply the numerator by the denominator diagonally. So for this question, I multiplied 3 by 16 and got 48. Then I multiplied 12 by 4 and got 48. That is how you prove that the ratios are equivalent. (Diagonal)

1. Does this seem fair?
No, it does not seem fair.

2. With what you know about proportion look and read what is in the image above. Does it seem just and fair? Why have you made this choice?
No, it does not seem fair. It does not seem fair because the homeless guy stole \$100 and was sentenced to 15 in prison. After stealing the money, the homeless guy felt guilty so the next day, he turned himself in. He was just hungry and needed some money to buy food. While some man stole \$3 billion and was sentenced only 40 months in prison. It isn't fair.

3. What would you do if you were the judge?
If I was the judge I would let the homeless man go off with a warning. But he would have to do 3 months of community service.