-10% is the change from 670 to 603
Calculation steps:
[( 603 - 670 ) ÷ 670] x 100 = -10%
Formula
Percentage change = [(603 - 670) / 670] x 100
Subtract the new number by the original number
603 - 670 = -67
-67 ÷ 670 = -0.1
-0.1 x 100 = -10%
Example