Converting Between Percentages and decimals | KS3 Maths Resources

What you need to know

Things to remember:

  • To turn a percentage into a decimal you have to divide by 100
  • To turn a decimal into a percentage you have to multiply by 100.
  • The best way to improve in this topic is practice multiplying and dividing by 100!

To start off with, let’s look at how we get from 100% to other percentages.



\div2 50%

\div4 25%

\div5 20%

\div10 10%

\div20 5%

\div50 2%

\div100 1%

But, we know that 100% represents a whole, or 100%=1, so we can use these same divisions to find some basic decimals.

 Percentage Decimal

100% 1

\div2 50% 0.5

\div4 25% 0.25

\div5 20% 0.2

\div10 10% 0.1

\div20 5% 0.05

\div50 2% 0.02

\div100 1% 0.01

When comparing these percentages and decimals, it is important to notice that all that has actually happened is, we have divided by 100.





All we need to do is remember that when we divide by 100, we move all digits two places to the right.

77\%\div100 \rightarrow7.7\rightarrow0.77


123\%\div100 \rightarrow12.3\rightarrow1.23


3.1\%\div100 \rightarrow0.31\rightarrow0.031


How about if we want to go in the opposite direction and turn a decimal into a percentage? Well, we do the opposite, we multiply by 100!

Hint: Remember, when we multiply by 100, we move all the digits to the left two places.







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KS3 Maths Revision Cards

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Example Questions

37.6\%\div100 \rightarrow3.76\rightarrow0.376




KS3 Maths Revision Cards

KS3 Maths Revision Cards

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