280% is the change from 80 to 304
Calculation steps:
[( 304 - 80 ) ÷ 80] x 100 = 280%
Formula
Percentage change = [(304 - 80) / 80] x 100
Subtract the new number by the original number
304 - 80 = 224
224 ÷ 80 = 2.8
2.8 x 100 = 280%
Example