90% is the change from 320 to 608
Calculation steps:
[( 608 - 320 ) ÷ 320] x 100 = 90%
Formula
Percentage change = [(608 - 320) / 320] x 100
Subtract the new number by the original number
608 - 320 = 288
288 ÷ 320 = 0.9
0.9 x 100 = 90%
Example