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.

Percentage

100%

\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.

100\div100=1

50\div100=0.5

20\div100=0.2

5\div100=0.5

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

 77\%=0.77

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

 123\%=1.23

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

 3.1\%=0.31

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.

0.13\times100\rightarrow1.3\rightarrow13

 0.13=13\%

1.67\times100\rightarrow16.7\rightarrow167

 1.67=167\%

0.002\times100\rightarrow0.02\rightarrow0.2

 0.002=0.2\%

Example Questions

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

 37.6\%=0.376

2.34\times100\rightarrow23.4\rightarrow234

 2.34=234\%

Need some extra help? Find a Maths tutor now

Or, call 020 3633 5145