3400% is the change from 20 to 700
Calculation steps:
[( 700 - 20 ) ÷ 20] x 100 = 3400%
Formula
Percentage change = [(700 - 20) / 20] x 100
Subtract the new number by the original number
700 - 20 = 680
680 ÷ 20 = 34
34 x 100 = 3400%
Example