65.8% is the change from 386 to 640
Calculation steps:
[( 640 - 386 ) ÷ 386] x 100 = 65.8%
Formula
Percentage change = [(640 - 386) / 386] x 100
Subtract the new number by the original number
640 - 386 = 254
254 ÷ 386 = 0.6580310880829016
0.6580310880829016 x 100 = 65.8%