How do I do percentages? Please explain like it would be like in a shop: for example whats 15% off of something.

Ok see for doing percentage it is very easy just divide it by the main number I mean see if there is a food price 10 dollars and it has 20%off then u divide 20/10x100 u divide it by the actual number and then multiply it by 100 so the answer of my 20/10x100 is 10x20/100 ok so the answer is 2. The price is 2

It looks like you multiply the two numbers and get the next two numbers so
5*5=25

pattern:5,5;25,25;625,625;390625,390625...