Sum of the decimal places = 7 .Since the last digit to the extreme right will be zero ( 5 * 4 = 20), so there will be 6 significant digits to the right of the decimal point....
Given Expression = (.53)³ - (.42)³- 3 x .58 x .42 x (.58-.42)= a³-b³ -3ab(a - b) = (a - b)³(where a = .58 and b=.42)= (.58 - .42 )³ = .16 x .16 x .16 = 0.004096
EXAMIANS