A ratio is a way to compare two or more units to one another to show a relationship.
It can be written in 3 different ways, as a fraction, with a colon, or with the word to.
For example, there are 3 dogs for every cat. This would be written as 3/1, 3:1, or 3 to 1. Each of these ways of writing the ratio is read the same way as 3 to 1.
Units are the ways that something is measured. In the example above, the units are dogs and cats. Units do NOT include numbers.
What are the units in the following problems?
1) 5 plates for 2 bowls
2) 2 boys: 3 girls
3) 4 blue blocks to 6 red blocks
Try to write each of the problems (1-3) from above in all the ways that a ratio can be written.
Notes from Class: