CBSE Book Class 8 Maths Activity 12

To make cuboids and cubes of given dimensions (4 x 3 x 2, 3 x 3 x 3) using unit cubes and to calculate the volume of each .

Learning Objective : To establish formulae for finding volumes of a cuboid and a cube.

Pre-requisite :Knowledge of volume.

Materials Required : Unit cubes.

Procedure :   For cuboid (4 x 3 x 2)

Step 1. Take four unit cubes and join them to make a row. [Fig. 12(a)]

Step 2. Make three such rows as in Step 1 and join them as shown in. Fig. 12(b)

Step 3. Make one more solid of the type as given in Fig. 12(b) using unit cubes and place it over the solid formed in Fig. 12(b). [See Fig. 12(c)].  Find the volume of the cuboid in Fig. 12(c) by counting the number of unit cubes.

Step 4. Repeat the activity by

(i) Taking 3 cubes in a row.

(ii) Taking 3 rows of 3 cubes in each layer.

(iii) Taking 3 layers to get a cube of dimensions 3 x 3 x 3 [ Fig. 12(d)].

Find the volume of the cube by counting the number of unit cubes.

Observation :
(i) Number of unit cubes used in the solid (cuboid) in Fig 12(c) = ............ Its volume = ...............cubic units.

(ii) Dimensions of this cuboid are 4 x 3 x ...........................

(iii) (Length x breath x height) of the cuboid = ......................... of the cuboid.

(iv) Number of unit cubes used in the solid (cube) in Fig. 12(d) = .................., Its volume = ......................... cubic units.

(v) Dimensions of this cube are 3 x .......... x 3.

(vi) Length x breath x height = length x length x length of the cube in Fig. 12(d) = ................. of the cube.

Please refer to the link below - CBSE Class 8 Maths Activity 12