10% is the change from 210 to 231
Calculation steps:
[( 231 - 210 ) ÷ 210] x 100 = 10%
Formula
Percentage change = [(231 - 210) / 210] x 100
Subtract the new number by the original number
231 - 210 = 21
21 ÷ 210 = 0.1
0.1 x 100 = 10%
Example