310% is the change from 200 to 820
Calculation steps:
[( 820 - 200 ) ÷ 200] x 100 = 310%
Formula
Percentage change = [(820 - 200) / 200] x 100
Subtract the new number by the original number
820 - 200 = 620
620 ÷ 200 = 3.1
3.1 x 100 = 310%
Example