I've been waiting for someone to ask this question. It's one of my favorite questions to answer.
percent means out of 100 so 1% = 1/100 and 40%=40/100 or 1/25 so for percent of a number, 'of' means multiply so 40% of 500= 40/100 times 500 or 20000/100 or 200
if you multiply a fraction by its recipricol (the number fliped upside down) the you will get 1 so if you multiply 1/2 by 2/1 then you will get 1
thus percent is out of 100 so 1%=1/100 25%=25/100 if you represent 45 out of something as 45/x then you multiply it by the reciprocal of the fraction that is supposed to be equal (1/2 =2/4) then you will get 1 so 45/x times reciprocal of 100/25 then you will get 1/1 or 4500/25x so you divide to find x and get 180 so 45 is 25% of 180
The following is extra as stated above 'of' can be taken as multiply so 45 is 25% of 180 can be rewriten as 45=25/100 times 180 but we don't know that 180 is the answer so we replace it with x then solve for x
