-89.55% is the change from 670 to 70
Calculation steps:
[( 70 - 670 ) ÷ 670] x 100 = -89.55%
Formula
Percentage change = [(70 - 670) / 670] x 100
Subtract the new number by the original number
70 - 670 = -600
-600 ÷ 670 = -0.8955223880597015
-0.8955223880597015 x 100 = -89.55%