357.14% is the change from 70 to 320
Calculation steps:
[( 320 - 70 ) ÷ 70] x 100 = 357.14%
Formula
Percentage change = [(320 - 70) / 70] x 100
Subtract the new number by the original number
320 - 70 = 250
250 ÷ 70 = 3.5714285714285716
3.5714285714285716 x 100 = 357.14%