5500% is the change from 15 to 840
Calculation steps:
[( 840 - 15 ) ÷ 15] x 100 = 5500%
Formula
Percentage change = [(840 - 15) / 15] x 100
Subtract the new number by the original number
840 - 15 = 825
825 ÷ 15 = 55
55 x 100 = 5500%
Example