write a percent for a $7.50 donation from a $100 check.

Question

7.5 percent???

7.5% = 75 OVER 100

yepp, 7.5%
but if you want some explanation, here's a picture. =]
i11.tinypic.c0m/44ipo50

make sure to change the "0" in the com to an "o"

dumbb

dumb