500% is the change from 70 to 420
Calculation steps:
[( 420 - 70 ) ÷ 70] x 100 = 500%
Formula
Percentage change = [(420 - 70) / 70] x 100
Subtract the new number by the original number
420 - 70 = 350
350 ÷ 70 = 5
5 x 100 = 500%
Example