1580% is the change from 50 to 840
Calculation steps:
[( 840 - 50 ) ÷ 50] x 100 = 1580%
Formula
Percentage change = [(840 - 50) / 50] x 100
Subtract the new number by the original number
840 - 50 = 790
790 ÷ 50 = 15.8
15.8 x 100 = 1580%
Example