285.71% is the change from 70 to 270
Calculation steps:
[( 270 - 70 ) ÷ 70] x 100 = 285.71%
Formula
Percentage change = [(270 - 70) / 70] x 100
Subtract the new number by the original number
270 - 70 = 200
200 ÷ 70 = 2.857142857142857
2.857142857142857 x 100 = 285.71%