87.13% is the change from 342 to 640
Calculation steps:
[( 640 - 342 ) ÷ 342] x 100 = 87.13%
Formula
Percentage change = [(640 - 342) / 342] x 100
Subtract the new number by the original number
640 - 342 = 298
298 ÷ 342 = 0.8713450292397661
0.8713450292397661 x 100 = 87.13%