Ratios

In this lesson, the objective is to write ratios as the relationship of one number to another number.

Definition:

A ratio is a comparison of two numbers that uses division.

The division is usually written as a fraction

Say for instance, you are in a classroom. In the classroom, there are boys and girls.

If there are 6 girls and 3 boys in that classroom, you can say that the ratio of boys to girls is 3/6

You can also write 3 to 6 or 3:6

3/6 is equal to 1/2 or 0.5 and it means that there are half as many boys as girls in the classroom.

However, the ratio of girls to boys is 6/3

6/3 is equal to 2 and it means that there are two times as many girls as boys in the classroom.

You can also define the following:

Ratio of girls to number of students in the classroom: 6/9

Ratio of boys to number of students in the classroom: 3/9

Ratio of number of students in the classroom to girls: 9/6

Ratio of number of students in the classroom to boys: 9/3

At this point you may have noticed that the order is important when defining a ratio. The number that comes after ' of ' is your numerator and the number that comes after ' to ' is your denominator.

ADD TO YOUR SOCIAL BOOKMARKS: Blink Del.icio.us Digg
Furl Google Simpy Spurl Technorati Y! MyWeb