38.59% is the change from 640 to 887
Calculation steps:
[( 887 - 640 ) ÷ 640] x 100 = 38.59%
Formula
Percentage change = [(887 - 640) / 640] x 100
Subtract the new number by the original number
887 - 640 = 247
247 ÷ 640 = 0.3859375
0.3859375 x 100 = 38.59%