-40% is the change from 525 to 315
Calculation steps:
[( 315 - 525 ) ÷ 525] x 100 = -40%
Formula
Percentage change = [(315 - 525) / 525] x 100
Subtract the new number by the original number
315 - 525 = -210
-210 ÷ 525 = -0.4
-0.4 x 100 = -40%
Example