2. VOLUME BY COUNTING CUBES Objective To understand the concept of volume in terms of counting cubes.

3.  Volume is the measure of the capacity of a container.  It is the measure of how much a container of a particular shape will hold - liquids, dry substances, etc.

4. = 1 centimetre cube 1cm = 1 cm³ One Unit of Volume is the “CUBIC CENTIMETRE” Volume is the amount of space a 3D - shape takes up Volumes by Counting Cubes

5. = 2 centimetre cubes 1cm = 2 cm³ This shape is made up of 1 centimetre cubes placed next to each other. What is its volume in cm³? 1cm Volumes by Counting Cubes

6. What is its volume in cm³ of these shapes. 5 cm 3 6 cm 3 5 cm 3 Volumes by Counting Cubes

7. Volume = 24 centimetre cube One unit of Volume is the “CUBIC CENTIMETRE” 2cm 3cm 4cm = 24 cm³ Volumes by Counting Cubes

8. a. ____ cm³ b. ____ mm³

10. VOLUMES BY COUNTING CUBES c. ____ cm 3 d. ___ cm 3

12. Now try these Exercises! Volume in term of cubes

17. OBJECTIVE: To understand how to calculate the volume of cuboids and cubes.

18. How can we find VOLUME of a cube? a All the sides (edges) of a cube have the same length. If each side has the length a, the formula for the volume V will be: L x L x L x a

19. Example 1 2cm Volume = l x l x l V = 2 x 2 x 2 V = 8 cm³ Working

20. 34cm Example 2 Working Volume = l x l x l V = 34 x 34 x 34 V = 393cm 3

21. Volume of a cuboid 4 layers of 18 cubes = 4 x 18= 72 centimetre cubes= 72 cm³ 18 cubes fit the base. = 1 centimetre cube = 1 cm³ 3cm 4cm 6cm

23. A short cut ! 6 = 72 cm³ Volume = length x Breadth x 4 x height length breadth height x 3Volume = 3cm 4cm 6cm

24. Volume = l x b x h V = 18 x 5 x 27 V = 2430 cm³ Example 1 18 cm 5 cm 27cm Heilander’s Porridge Oats Working

25. 2 cm 3 mm 4 mm 7 cm 6 cm 9 ft 4 ft 6 ft Volume of Cuboids Volume = 4 mm x 3 mm x 3 mm = 36 mm 3 Volume = 2 cm x 7 cm x 6 cm = 84 cm 3 36 mm 3 84 cm 3 Volume = 9 ft x 4 ft x 6 ft = 216 ft 3 216 ft 3 Volume l x w x h ? yards 3

26. Now try these Exercises! Volume of cuboids and cubes

30. 4cm 6cm It has a height of 6cm. What is the size of the radius ? Volume = cross section x height Calculate the area of the circle: A =  r 2 A = 3.14 x 2 x 2 A = 12.56 cm 2 Calculate the volume: V =  r 2 x h V = 12.56 x 6 V = 75.36 cm 3 The formula for the volume of a cylinder is: V =  r 2 h r = radius h = height. 2cm

31. Radius is the half of diameter The formula for the volume of a cylinder is: V =  r 2 h r = radius h = height.