2100% is the change from 40 to 880
Calculation steps:
[( 880 - 40 ) ÷ 40] x 100 = 2100%
Formula
Percentage change = [(880 - 40) / 40] x 100
Subtract the new number by the original number
880 - 40 = 840
840 ÷ 40 = 21
21 x 100 = 2100%
Example