100% is the change from 215 to 430
Calculation steps:
[( 430 - 215 ) ÷ 215] x 100 = 100%
Formula
Percentage change = [(430 - 215) / 215] x 100
Subtract the new number by the original number
430 - 215 = 215
215 ÷ 215 = 1
1 x 100 = 100%
Example