40.94% is the change from 640 to 902
Calculation steps:
[( 902 - 640 ) ÷ 640] x 100 = 40.94%
Formula
Percentage change = [(902 - 640) / 640] x 100
Subtract the new number by the original number
902 - 640 = 262
262 ÷ 640 = 0.409375
0.409375 x 100 = 40.94%