0.39799476 or 0.40
break it down into smaller pieces.
0.4000 x 0.8000
0.0800 x 0.0100
0.0090 x 0.0020
0.0009 x 0.0004
once you have your answers, just add. (0.39799476)
however, you should simplify, which turns it into 0.40. ^^
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