15.94% is the change from 640 to 742
Calculation steps:
[( 742 - 640 ) ÷ 640] x 100 = 15.94%
Formula
Percentage change = [(742 - 640) / 640] x 100
Subtract the new number by the original number
742 - 640 = 102
102 ÷ 640 = 0.159375
0.159375 x 100 = 15.94%