8100% is the change from 10 to 820
Calculation steps:
[( 820 - 10 ) ÷ 10] x 100 = 8100%
Formula
Percentage change = [(820 - 10) / 10] x 100
Subtract the new number by the original number
820 - 10 = 810
810 ÷ 10 = 81
81 x 100 = 8100%
Example