250% is the change from 2 to 7
Calculation steps:
[( 7 - 2 ) ÷ 2] x 100 = 250%
Formula
Percentage change = [(7 - 2) / 2] x 100
Subtract the new number by the original number
7 - 2 = 5
5 ÷ 2 = 2.5
2.5 x 100 = 250%
Example