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I am learning to work out percentages of amounts.

%

Percentages are out of 100.

100

Tim got 18 out of 25 in a test and Scott got 45 out of 50 in a test. Who got the best result ?

We need to change the tests into percentages so that we can compare them.

Let’s start by changing Tim’s score (18 out of 25) into a percentage.

0 25 50 10075

18

X 4

X 4

72

25

18

100

72

Multiplying the numerator and denominator by 4 will give us an equivalent fraction out of 100

72%

Now we need to turn Scott’s score (45 out of 50 into a percentage).

0 25 50 10075

45

X 2

X 2

90

50

45

100

90

Multiplying the numerator and denominator by 2 will give us an equivalent fraction out of 100

90%

Tim scored 72% and Scott scored 90%. It is now easy to see that Scott got the best result.

Room 13 completed a maths test out of 40. Help the teacher convert some student scores into percentages.

0% 25% 50% 100%75%

400

If the test is out of 40. What would 50% be?

20

What would 25% be? Tip: 25% is half of a half.

10 30

What would 75% be? Tip: a half plus one quarter.

The number line above is called a double number line. You can see it is very helpful to imagine when converting scores into percentages.

Room 9 completed a science quiz which was out of 16. Help the teacher convert some student scores into percentages.

0% 25% 50% 100%75%

160

If the test is out of 16. What would 50% be?

8

What would 25% be? Tip: 25% is half of a half.

4 12

What would 75% be? Tip: a half plus one quarter.

What would a score of 2 out of 16 be as a percentage?

2

You can see that 2 is exactly halfway between 0 and 25%.

Half of 25% is 12.5%.

12.5%

Now try these questions on your own.

1)

2)

3)

4)

5)

Click again when you have worked out all your answers.

Need some more practise? Try pg34 & 35 of Teacher Tools Fractions, Decimals and Percentages Book Numeracy resources

6)

7)

8)

9)

10)

25%

50%

50%

25%

20%

33%

20%

48%

150%

75%

Change these fractions into percentages

24

6

16

8

48

24

32

8

10

2

27

9

25

5

25

12

6

9

16

12