-10% is the change from 710 to 639
Calculation steps:
[( 639 - 710 ) ÷ 710] x 100 = -10%
Formula
Percentage change = [(639 - 710) / 710] x 100
Subtract the new number by the original number
639 - 710 = -71
-71 ÷ 710 = -0.1
-0.1 x 100 = -10%
Example