Tuesday, October 18, 2011

Josh L's Proportion Post


two-term ratio-
compares two quantities measured in the same units.

three-term ratio-
compares three quantities measured in the same units.

part-to-part ratio-
compares different parts of a group to each other.

part-to-whole ratio-
compares one part of a group to the whole group.

a comparison of two quantities measured in different units. $ 1.69 per 100 grams or $1.69/100g is a rate for purchasing bulk food. 72 beats/min is a heart rate.

proportion- an equation which states that two ratios or fractions are equal.

1. 5 hours to travel 360 miles is about _____ mph
Answer: 72 mph

2. As a playgroup worker, if I increase the amount of apple juice I am serving at the playgroup from 25 ml to 100 ml, how much should I increase the the orange juice to, to keep the quantities in the same proportion? The orange juice is 50 ml to start with.
Answer: 200 ml

What are the three ways you can prove that equivalent ratio statements are true?
3/4 = 12/16 or 4/9 = 16/32


1. First, you can go diagonally. You can multiply the top left to the bottom right and the top right to the bottom left.
2. Secondly, you can do it vertically. You divide the numerator to the denominator for each ratios.
3. Lastly, you can divide the top left to the top right. Then, you divide the bottom left to the bottom right.

This is a video about a class doing proportions. Enjoy!

We are starting to engage in discussions about social justice. What do you think about this image below.

1. Does this seem fair?
No, I don't think this is very fair at all.

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's not fair. I've made this choice because the first man stole $ 3 billion and was sentenced for 40 months in jail (slightly less than six years.) Then, the other guy stole $ 100 bill because he was very hungry. The next day, he felt guilty and surrendered himself. He was sentenced for 15 years in prison.

What would you have done if you were the judge?
If I was the judge, I would've just made it a warning. Then I would give the hungry man a $ 100 so he could buy food and stay at the detox center.

Here is some link to help you with proportions:



I hope this helps you!