Lesson 1: Understand Ratios6.AT.1

I can…

I can write and describe a ratio that compares two quantities.

Key words

• Ratio — A way to compare two amounts, like 3 to 2.
• Comparison — Looking at two or more amounts to see how they are related.
• Part-to-part — A ratio comparing one part of a group to another part.
• Part-to-whole — A ratio comparing one part to the whole group.
• Colon notation — Writing a ratio with two dots between the numbers, like 3:2.

Steps

1. Chef Reyes uses 3 cups of flour for every 2 cups of sugar.
2. I am comparing two amounts: flour and sugar.
3. I write flour to sugar, in that order, as 3 to 2.
4. In colon notation I write it as 3:2.
5. So the ratio of flour to sugar is 3:2.

Try it

A bag of trail mix contains 8 peanuts and 5 raisins. What is the ratio of raisins to total pieces?

Check your answer

5:13

Total pieces = 8 + 5 = 13. The ratio of raisins to total is 5:13.

Sentence starter

I know ___ because ___.

Goal: I can explain a comparison using the words ratio, part-to-part, part-to-whole, and colon notation.