909.38% is the change from 64 to 646
Calculation steps:
[( 646 - 64 ) ÷ 64] x 100 = 909.38%
Formula
Percentage change = [(646 - 64) / 64] x 100
Subtract the new number by the original number
646 - 64 = 582
582 ÷ 64 = 9.09375
9.09375 x 100 = 909.38%
Example