In math, a ratio compares two numbers. We always put a colon between the two numbers.
We have a 1:2 chance of winning
We have five pieces of fruit, and two of the five are peaches. We say that ratio of peaches is 2:5.
There are thirty children in the classroom, and 13 of the children are girls. We write that ratio as 13:30.
Use a colon when writing a ratio which shows the relationship between two amounts.
It’s your turn. Use a colon to write the ratio that 5 out of 10 dogs have fleas. Did you write 5:10? Good for you.