7.34% is the change from 640 to 687
Calculation steps:
[( 687 - 640 ) ÷ 640] x 100 = 7.34%
Formula
Percentage change = [(687 - 640) / 640] x 100
Subtract the new number by the original number
687 - 640 = 47
47 ÷ 640 = 0.0734375
0.0734375 x 100 = 7.34%