1985% is the change from 40 to 834
Calculation steps:
[( 834 - 40 ) ÷ 40] x 100 = 1985%
Formula
Percentage change = [(834 - 40) / 40] x 100
Subtract the new number by the original number
834 - 40 = 794
794 ÷ 40 = 19.85
19.85 x 100 = 1985%
Example