27.88% is the change from 642 to 821
Calculation steps:
[( 821 - 642 ) ÷ 642] x 100 = 27.88%
Formula
Percentage change = [(821 - 642) / 642] x 100
Subtract the new number by the original number
821 - 642 = 179
179 ÷ 642 = 0.278816199376947
0.278816199376947 x 100 = 27.88%