A ratio is a comparison of two (or more) numbers that have the same units.
eg Jonah earned $300, Jess earned $500.
This can be written as a ratio of 300 : 500.
We say 300 to 500.
This ratio can be simplified to 3 : 5.
This means for every $3 Jonah earned, Jess earned $5.
Order is important:Â 5 : 3 is not the same as 3 : 5.