Solve Problems by Finding Percentages of Given Amounts

In this activity, we will find percentages of given amounts!

 

Recap of common percentages (Make a note of these!)

 

10%  - We divide the amount by 10 because 10% is one tenth

50% - We divide the amount by 2 because it is a half

25% - We divide the amount by 4 because it is a quarter

75% - is three-quarters, so we can divide by 4 and multiply by 3

1%  - We divide the amount by 100 because 1% is one hundredth

We can use these simple percentages to find other percentages!

 

Example 1

Find 20% of 360

 

Answer

We know how to find 10%  - we divide by 10

20% is made up of 2 x 10% (2 lots of 10%)

We can find 10% then multiply by 2

 

10% = 360 ÷ 10 = 36

20% = 36 x 2 = 72

 

In this activity, we are looking at problems!

 

 

Example

There are 160 students in Year 7.

15% of them come to school by car.

How many students come to school by car?

 

Answer

We know how to find 10%  - we divide by 10

5% is half of 10% (Divide 10% by 2)

We can find 15% by adding 10% and 5% amounts together.

 

10% = 160 ÷ 10 = 16

5%  =  10% ÷ 2 = 16 ÷ 2 = 8

15%  = 10% + 5% = 16 + 8 = 24

 

24 students come to school by car!

 

 

Let's try some questions!