3X2X( 1.3- 1)

=6X0.3

= 1.8 (cubic decimeter)

Analysis: the volume formula of a cuboid is abh. As can be seen from the title, the stone rose by 0.3dm after it was put in. Then, 0.3dm is like the height of a glass ball, which is solved by a rectangular formula.

5.

This tin box is 4 cm high.

Tin box bottom area =768/4= 192 (square centimeter);

The length of the bottom of the tin box is 32-4-4=24 (cm).

The width of the bottom of the tin box is 192/24=8 (cm).

Rectangular iron sheet, 32 cm long, 8+4+4 = 16 (cm) wide,

It turns out that the area of this iron sheet is:

32* 16=5 12 (square centimeter)