106.45% is the change from 310 to 640
Calculation steps:
[( 640 - 310 ) ÷ 310] x 100 = 106.45%
Formula
Percentage change = [(640 - 310) / 310] x 100
Subtract the new number by the original number
640 - 310 = 330
330 ÷ 310 = 1.064516129032258
1.064516129032258 x 100 = 106.45%