70% is the change from 100 to 170
Calculation steps:
[( 170 - 100 ) ÷ 100] x 100 = 70%
Formula
Percentage change = [(170 - 100) / 100] x 100
Subtract the new number by the original number
170 - 100 = 70
70 ÷ 100 = 0.7
0.7 x 100 = 70%
Example