840% is the change from 40 to 376
Calculation steps:
[( 376 - 40 ) ÷ 40] x 100 = 840%
Formula
Percentage change = [(376 - 40) / 40] x 100
Subtract the new number by the original number
376 - 40 = 336
336 ÷ 40 = 8.4
8.4 x 100 = 840%
Example