50% is the change from 644 to 966
Calculation steps:
[( 966 - 644 ) ÷ 644] x 100 = 50%
Formula
Percentage change = [(966 - 644) / 644] x 100
Subtract the new number by the original number
966 - 644 = 322
322 ÷ 644 = 0.5
0.5 x 100 = 50%
Example