my favourite #mathsfact : X% of Y = Y% of X.

try it.
12% of 50 = 6
50% of 12 = 6.

or another example:
25% of 80 = ¼ of 80 = 20.
80% of 25 = ⁴/5 of 25 = 20.

what're your favourite #maths (or #math if you must) #funfacts ?