337.5% is the change from 64 to 280
Calculation steps:
[( 280 - 64 ) ÷ 64] x 100 = 337.5%
Formula
Percentage change = [(280 - 64) / 64] x 100
Subtract the new number by the original number
280 - 64 = 216
216 ÷ 64 = 3.375
3.375 x 100 = 337.5%
Example