## Wednesday, October 12, 2011

### Sheila's Proportion Post

Definitions:
Ratio-A ratio is a comparison of quantities hat have the same units. Ratio can be written in many different ways.
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.
Rate- It is a comparison of two quantities measured in different units.
Proportion- An equation which states that two ratios or fractions are equal.

1) 5 hours to travel 360 miles in about 72mph

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.

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.

Task 4) Here is a link to see a video about a class doing proportions. ENJOY !