-22.52% is the change from 826 to 640
Calculation steps:
[( 640 - 826 ) ÷ 826] x 100 = -22.52%
Formula
Percentage change = [(640 - 826) / 826] x 100
Subtract the new number by the original number
640 - 826 = -186
-186 ÷ 826 = -0.22518159806295399
-0.22518159806295399 x 100 = -22.52%