How do I find if a number is a multiple of 8?

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Answer 1 · 2016-04-04T14:30:34

Please see the process and reason below.

Just check the last three digits of the number.

If they are divisible by #8#, the entire number is divisible by #8#.

For example, last three digits of #53927592# are #592# and they are divisible by #8# as #592=74xx8#.

Hence, #53927592# is divisible by #8# and #53927592=6740949xx8#.

The reason is that as the number can be expressed as
#YYYYYZ Z Z=YYYYYxx1000+Z Z Z#

= #YYYYYxx125xx8+Z Z Z#.

As #YYYYYxx125xx8# is divisible by #8#, if #Z Z Z# is divisible by #8#, #YYYYYZ Z Z# is divisible by #8#.