52.34% is the change from 640 to 975
Calculation steps:
[( 975 - 640 ) ÷ 640] x 100 = 52.34%
Formula
Percentage change = [(975 - 640) / 640] x 100
Subtract the new number by the original number
975 - 640 = 335
335 ÷ 640 = 0.5234375
0.5234375 x 100 = 52.34%