400% is the change from 42 to 210
Calculation steps:
[( 210 - 42 ) ÷ 42] x 100 = 400%
Formula
Percentage change = [(210 - 42) / 42] x 100
Subtract the new number by the original number
210 - 42 = 168
168 ÷ 42 = 4
4 x 100 = 400%
Example