390% is the change from 70 to 343
Calculation steps:
[( 343 - 70 ) ÷ 70] x 100 = 390%
Formula
Percentage change = [(343 - 70) / 70] x 100
Subtract the new number by the original number
343 - 70 = 273
273 ÷ 70 = 3.9
3.9 x 100 = 390%
Example