2750% is the change from 12 to 342
Calculation steps:
[( 342 - 12 ) ÷ 12] x 100 = 2750%
Formula
Percentage change = [(342 - 12) / 12] x 100
Subtract the new number by the original number
342 - 12 = 330
330 ÷ 12 = 27.5
27.5 x 100 = 2750%
Example