150% is the change from 6 to 15
Calculation steps:
[( 15 - 6 ) ÷ 6] x 100 = 150%
Formula
Percentage change = [(15 - 6) / 6] x 100
Subtract the new number by the original number
15 - 6 = 9
9 ÷ 6 = 1.5
1.5 x 100 = 150%
Example