In some situations, it can be useful to convert a decimal number to a percentage or vice versa. The following concept sheet outlines the methods for correctly performing these conversions.
The method for converting a decimal number to a percentage is straightforward.
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Multiply the decimal number by |100.|
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Add the % symbol to the right of the result.
Express |0{.}562| as a percentage.
- Multiply the decimal number by |100| ||0{.}562\times 100=56{.}2||
- Add the % symbol to the right of the result ||56{.}2\ \%||
This means that |0{.}562=56{.}2\ \%|
Express |1{.}4| as a percentage.
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Multiply the decimal number by |100| ||1{.}4\ \times 100=140||
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Add the % symbol to the right of the result ||140\ \%||
This means that |1{.}4=140\ \%|
The method of converting a percentage to its decimal number equivalent is also straightforward.
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Remove the percent symbol (%).
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Divide the number by |100.|
Express |60\ \%| as a decimal number.
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Remove the percent symbol (%) ||60||
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Divide the number by |100| ||60\div 100=0{.}6||
This means that |60\ \%=0{.}6.|
Express |120{.}5\ \%| as a decimal number.
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Remove the percent symbol (%) ||120{.}5||
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Divide the number by |100| ||120{.}5\div 100=1{.}205||
This means that |120{.}5\ \%=1{.}205.|
The same method is used to convert from a periodic number, or a repeating decimal number, to a percentage and vice versa.