-23% is the change from 1000 to 770
Calculation steps:
[( 770 - 1000 ) ÷ 1000] x 100 = -23%
Formula
Percentage change = [(770 - 1000) / 1000] x 100
Subtract the new number by the original number
770 - 1000 = -230
-230 ÷ 1000 = -0.23
-0.23 x 100 = -23%