109% is the change from 400 to 836
Calculation steps:
[( 836 - 400 ) ÷ 400] x 100 = 109%
Formula
Percentage change = [(836 - 400) / 400] x 100
Subtract the new number by the original number
836 - 400 = 436
436 ÷ 400 = 1.09
1.09 x 100 = 109%
Example