1970% is the change from 40 to 828
Calculation steps:
[( 828 - 40 ) ÷ 40] x 100 = 1970%
Formula
Percentage change = [(828 - 40) / 40] x 100
Subtract the new number by the original number
828 - 40 = 788
788 ÷ 40 = 19.7
19.7 x 100 = 1970%
Example