71.43% is the change from 490 to 840
Calculation steps:
[( 840 - 490 ) ÷ 490] x 100 = 71.43%
Formula
Percentage change = [(840 - 490) / 490] x 100
Subtract the new number by the original number
840 - 490 = 350
350 ÷ 490 = 0.7142857142857143
0.7142857142857143 x 100 = 71.43%