-70% is the change from 770 to 231
Calculation steps:
[( 231 - 770 ) ÷ 770] x 100 = -70%
Formula
Percentage change = [(231 - 770) / 770] x 100
Subtract the new number by the original number
231 - 770 = -539
-539 ÷ 770 = -0.7
-0.7 x 100 = -70%
Example