Ratio is a comparison of two or more quantities expressed in fraction or colon form. A ratio can be reduced to its simplest terms by dividing both numbers by their greatest common factor. Examples show how to determine the ratio between two quantities like the number of girls and boys in a room, and how to simplify ratios into their lowest terms.

1. Ratio

2. Ratio – is a comparison of two or more
numbers or quantities.
• 4 apples to 8 avocados
- 4:8 or Four is to eight or
4
8
-
4
8
÷
4
4
=
1
2
or 1:2 is the equivalent ratio
- Equivalent ratio are obtained by reducing the ratio
to lowest terms by getting the GCF.

3. Colon Form Fraction Form
4:8
4
8
2:4
2
4
1:2
1
2
The first and second numbers refer to the
first and second quantities, respectively. Thus,
4:8 is different from 8:4
The colon (:) and fraction bar ( ̶ ) are both
read as “is to”.
The ratio can be written in colon form and
in fraction form.

4. Example:
The number of girls in the room are 12 and
the boys are 10. What is the ratio of
girls to boys?
girls : boys = 12:10 or
12
10
12
10
÷
2
2
=
6
5

5. Try:
Express each ratio to its simplest form.
8
10
=
5
15
=
9
12
=
8
10
÷ 2
2
=
4
5
5
15
÷
5
5
=
1
3
9
12
÷
3
3
=
3
4