-89.88% is the change from 820 to 83
Calculation steps:
[( 83 - 820 ) ÷ 820] x 100 = -89.88%
Formula
Percentage change = [(83 - 820) / 820] x 100
Subtract the new number by the original number
83 - 820 = -737
-737 ÷ 820 = -0.8987804878048781
-0.8987804878048781 x 100 = -89.88%