103.17% is the change from 315 to 640
Calculation steps:
[( 640 - 315 ) ÷ 315] x 100 = 103.17%
Formula
Percentage change = [(640 - 315) / 315] x 100
Subtract the new number by the original number
640 - 315 = 325
325 ÷ 315 = 1.0317460317460319
1.0317460317460319 x 100 = 103.17%