506.06% is the change from 66 to 400
Calculation steps:
[( 400 - 66 ) ÷ 66] x 100 = 506.06%
Formula
Percentage change = [(400 - 66) / 66] x 100
Subtract the new number by the original number
400 - 66 = 334
334 ÷ 66 = 5.0606060606060606
5.0606060606060606 x 100 = 506.06%