-14.69% is the change from 640 to 546
Calculation steps:
[( 546 - 640 ) ÷ 640] x 100 = -14.69%
Formula
Percentage change = [(546 - 640) / 640] x 100
Subtract the new number by the original number
546 - 640 = -94
-94 ÷ 640 = -0.146875
-0.146875 x 100 = -14.69%