 # Percentages What are Percentages?. Percentages are measures out of a 100 Percentages.

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Percentages What are Percentages?

Percentages are measures out of a 100 Percentages

This grid is made up of 100 squares. We will use it to look at percentages.

In this case, fifty percent is shaded We write this as 50%

The following grids also show 50%.

These grids show 25%

And these show 10%

Can you name these percentages? 40%70% 5%64% ?? ??

Finding Simple Percentages of Numbers Percentages

Finding Fifty Percent (50%) 50% is the easiest percentage to find. All you have to do is halve your number.

Here is an example Find 50% of 70 70  35

Why do you divide by 2? The reason you divide by two is because there are two fifties in one hundred. 100  50 = 2

Find 50% of the following numbers. 40 50% of 40 =20 18 50% of 18 =9 130 50% of 130 = 65 15 50% of 15 =7.5

Finding Ten Percent (10%) 10% is an easy percentage to find. All you have to do is divide your number by ten.

Here is an example Find 10% of 40 40  4

Why do you divide by 10? The reason you divide by ten is because there are ten tens in one hundred. 100  10 = 10

Find 10% of the following numbers. 60 10% of 60 =6 150 10% of 150 =15 240 10% of 240 = 24 45 10% of 45 =4.5

Finding One Percent 1% is a little bit more difficult to find. To work out 1% you divide your number by one hundred.

Here is an example Find 1% of 120 120  1.2

Why do you divide by 100? The reason you divide by one hundred is because there are one hundred ones in one hundred. 100  100 = 1

Find 1% of the following numbers. 200 1% of 200 =2 1500 1% of 1500 =15 50 1% of 50 = 0.5 25 1% of 25 =0.25

Calculating Percentages without a Calculator. Percentages

160 Finding various percentages of 160.

160 Calculate 50% of 160 50% of 160  80

160 50% of 160  80 25% is half of 50% 25%  40

160 50% of 160  80 25%  40 75% is 50% + 25% 75%  120

160 50% of 160  80 25%  40 75%  120 10% is 160  10 10%  16

160 50% of 160  80 25%  40 75%  120 10%  16 20% is double 10% 20%  

160 50% of 160  80 25%  40 75%  120 10%  16 20%   and 40% is double 20% 40%  64

160 50% of 160  80 25%  40 75%  120 10%  16 20%   40%  64 1% is 160  100 1%  

160 50% of 160  80 25%  40 75%  120 10%  16 20%   40%  64 1%   2% is double 1% 2%  3.2

160 50% of 160  80 25%  40 75%  120 10%  16 20%   40%  64 1%   2%  3.2 and 9% is 9 x 1% 9%  14.4

160 50% of 160  80 25%  40 75%  120 10%  16 40%  64 20%   1%   2%  3.2 9%  14.4 and 9% is 9 x 1%

Challenge Find 63% of 250.

250 50% of 250  125 Calculate 50% of 250

Calculate 10% of 250 250 50% of 250  125 10%  25

60% = 50% + 10% 250 50% of 250  125 10%  25 60%  150 +

Calculate 1% of 250 250 50% of 250  125 10%  25 60%  150 + 1%  2.5

3% is 3 x 1% 250 50% of 250  125 10%  25 60%  150 + 1%  2.5 3%  7.5

63% is 60% + 3% 250 50% of 250  125 10%  25 60%  150 + 1%  2.5 3%  7.5 63%  157.5

and 9% is 9 x 1% 250 50% of 250  125 10%  25 1%  2.5 60%  150 3%  7.5 63%  157.5 +

Calculating Percentages with a Calculator. Percentages

The general method used here is to find 1%, then calculate the percentage you are looking for. For example, to find 21% of a number, you would divide it by 100, then multiply by 21.

Calculating 21% of 80 Use your calculator to find the answer to this problem. 80  100 x 21 = ?

Calculating 21% of 80 Use your calculator to find the answer to this problem. 80  100 x 21 = 16.8

Calculating 83% of 155 Use your calculator to find the answer to this problem. 155  100 x 83 = ?

Calculating 83% of 155 Use your calculator to find the answer to this problem. 155  100 x 83 = 128.65

Try these… 1. 18% of 60 2. 32% of 82 3. 77% of 144 4. 99% of 150 5. 52% of 52 6. 1.5% of 16 7. 41.7% of 88 = 10.8 = 26.24 = 110.88 = 148.5 = 527.04 = 24 = 36.08

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