10% is the change from 640 to 704
Calculation steps:
[( 704 - 640 ) ÷ 640] x 100 = 10%
Formula
Percentage change = [(704 - 640) / 640] x 100
Subtract the new number by the original number
704 - 640 = 64
64 ÷ 640 = 0.1
0.1 x 100 = 10%
Example