857.14% is the change from 70 to 670
Calculation steps:
[( 670 - 70 ) ÷ 70] x 100 = 857.14%
Formula
Percentage change = [(670 - 70) / 70] x 100
Subtract the new number by the original number
670 - 70 = 600
600 ÷ 70 = 8.571428571428571
8.571428571428571 x 100 = 857.14%