80% is the change from 340 to 612
Calculation steps:
[( 612 - 340 ) ÷ 340] x 100 = 80%
Formula
Percentage change = [(612 - 340) / 340] x 100
Subtract the new number by the original number
612 - 340 = 272
272 ÷ 340 = 0.8
0.8 x 100 = 80%
Example