680.49% is the change from 82 to 640
Calculation steps:
[( 640 - 82 ) ÷ 82] x 100 = 680.49%
Formula
Percentage change = [(640 - 82) / 82] x 100
Subtract the new number by the original number
640 - 82 = 558
558 ÷ 82 = 6.804878048780488
6.804878048780488 x 100 = 680.49%