706.25% is the change from 80 to 645
Calculation steps:
[( 645 - 80 ) ÷ 80] x 100 = 706.25%
Formula
Percentage change = [(645 - 80) / 80] x 100
Subtract the new number by the original number
645 - 80 = 565
565 ÷ 80 = 7.0625
7.0625 x 100 = 706.25%
Example