Sources/references (March 2019)
Fascinating little life hack, for doing percentages:
x% of y = y% of x
So, for example, if you needed to work out 4% of 75 in your head, just flip it and and do 75% of 4, which is easier.
— Ben Stephens (@stephens_ben) March 3, 2019
Updated reference June 2021
Pink Pencil Math did a video on TikTok which has over 18 million views. Definitely watch it!
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