Converting between Decimals, Fractions and Percentages

Comparing Fractions with Percentages

• Percent simply means “out of 100”• So 25% means 25 out of 100

– or, 25 per 100

• Or, written as a fraction:• 25/100• This can be simplified to: • 1/4

Converting Percentages to Fractions

To convert from percentage to fraction, put the number over 100 then simplify.

30%

80%

Converting Percentages to Fractions

To convert from percentage to fraction, put the number over 100 then simplify.

30% = 30/100 = 3/10

80% = 80/100 = 8/10 = 4/5

Convert these into fractions

1. 1%

2. 10%

3. 20%

4. 50%

5. 75%

6. 5%

7. 45%

8. 28%

Converting Fractions to Percentages

Divide 100 by the the bottom number and then multiply the result by the top number.

=

Converting Fractions to Percentages

Divide 100 by the the bottom number and then multiply the result by the top number.

= 100 ÷ 5 = 20

20 x 2 = 40

= 40%

Convert these into percentages

1.

2.

3.

4.

5.

Converting Decimals to Percentages and vice versa

• Look at the decimal point. Move it along two places to the right and then you will have the percentage.

0.31 = 31%

4.25 = 425%• When converting from a percentage to a

decimal, simply move the decimal point back two places to the left.

26% = 0.26

Converting Fractions to Decimals

Start with the same method used with percentages.

= 100 ÷ 5 = 20

20 x 2 = 40%

Now move the decimal point two places to the left

40 = 0.40 (or 0.4)

Activity

• In pairs, complete the Fractions to Decimals activity.

• On Moodle, this is the file ‘frac-to-dec.docx’