Percentages What does it mean Percent means out

Percentages

What does it mean? • Percent means ‘out of 100’ • % is a short way of writing percent • E. g. 20% of 100 is the same as 20 out of 100

So… • You can write percentages as fractions • For example 20%20 100 Put the percentage on top Put 100 at the bottom of the fraction

Calculating percentages • In the exam you will need to calculate the percentage of something. • In such cases of means multiply X.

Example two Writing percentages out this way helps calculator entries

Lets practice one together now. . Rob teaches a fitness class of twenty people. 65% of the class are women, how many members are women? 65 % of 20 13 members are women 65 X 20 100 65 ÷ 100 X 20

Another type of percentage question • 115 students from Capel Manor were in a cooking competition. 21 of them made it through to the final round. What percentage of students made it to the final round? 21 115 x 100 = 18. 2 % 21 ÷ 115 x 100 = 18. 2 % 21 people out of 115 made it through then x 100 to get the %

Another type of percentage question • There are 18 girls in a class and 48 boys. What percentage of students are girls? First find the total number of students in the class. 18 + 48= 66 Then work out the percentage of girls. 18 66 x 100 = 27. 2% 18 ÷ 66 x 100 = 27. 2 % 18 people out of 66 are girl then x 100 to get the %

Calculating percentage increase • Sometimes, you may need to calculate a percentage increase • If so, you need to find the ‘percentage of’ first. Then add it to the original number.

Calculating percentage decrease • Sometimes, you may need to calculate a percentage decrease • If so, you need to find the ‘percentage of’ first. Then minus it from the original number.