900% is the change from 77 to 770
Calculation steps:
[( 770 - 77 ) ÷ 77] x 100 = 900%
Formula
Percentage change = [(770 - 77) / 77] x 100
Subtract the new number by the original number
770 - 77 = 693
693 ÷ 77 = 9
9 x 100 = 900%
Example