To find the % of a given number use the following steps :
1) Obtain the number, say 80 apples.
2) Let the percent as 35%.
3) 35% of x
4) write these as a proportion as 35/100 = ?/80
5) Now cross multiply and find the value of "?" mark.
100x = 2800
100x/100 = 2800/100
x = 28
She gave her friend 28 apples.