(0.4× 0.5+0.4× 0.6+0.5× 0.6 )× 2-(0.6× 0.4) =1.24 (square decimeter) Find out which ones are unnecessary.

0.4 square decimeter =0.004 square meter. Turn what needs to be consumed into square meters.

1.24+0.004= 1.244 square meters add up to figure out what a * * needs.

Answer: Prepare 1.244 square meters of plastic board.

0.6×0.4×0.5=0. 12 (cubic decimeter) Because the thickness can be ignored, the volume can be directly calculated by the formula V=abh.

A: The volume of this plastic box is 0. 12 cubic decimeter.

Is it a supplementary exercise for primary school mathematics, or the first volume of the sixth grade?