Expressing Fractions as Ratios, Decimals, and Percentages - JSS2 Mathematics Lesson Note

Fractions

A fraction represents a part of a whole. It is written as 

𝑎/𝑏, where 

𝑎 is the numerator (the number of parts you have), and 

𝑏 is the denominator (the total number of equal parts the whole is divided into).

For example, 

3/4 means 3 out of 4 equal parts.

Ratios

A ratio compares two quantities. It is written as 

𝑎:𝑏.

For example, if you have 3 apples and 4 oranges, the ratio of apples to oranges is 3:4.

Fractions can be expressed as ratios. The fraction 

¾ can be seen as the ratio 3:4.

Decimals

A decimal is another way to represent a fraction. To convert a fraction to a decimal, you divide the numerator by the denominator.

For example:

¾= 3÷4 =0.75

Percentages

A percentage is a fraction of 100. To convert a fraction to a percentage, you multiply the fraction by 100.

For example:

¾= 0.75×100 =75%