-7.23% is the change from 830 to 770
Calculation steps:
[( 770 - 830 ) ÷ 830] x 100 = -7.23%
Formula
Percentage change = [(770 - 830) / 830] x 100
Subtract the new number by the original number
770 - 830 = -60
-60 ÷ 830 = -0.07228915662650602
-0.07228915662650602 x 100 = -7.23%