1. Measuring Volume

2. What is volume? volume – the amount of space something fills
the volume of solids are commonly measured in cubic centimetres (cm3) or cubic meters (m3)
the volume of liquids (or gases) are often measured in litres (l) or millilitres (ml)
1 ml = 1 cm3
1,000 ml = 1 litre

3. Finding the Volume of a Regular Solid
regular solid – an object that has a structure that follows a set pattern, such that it has set angles (90 degrees for example) between its edges and faces
the volume of regular solids with edges and faces that are square (such as a cube or a rectangular solid) is found by multiplying the height by the length by the width

4. Finding the Volume of a Regular Solid
10 cm
10 cm
10 cm
Volume = height x length x width
Volume of this cube = 10 cm x 10 cm x 10 cm = 1,000 cm3

5. Finding the Volume of a Regular Solid
4 cm
10 cm
2 cm
Volume of this rectangular solid =
4 cm x 2 cm x 10 cm = 80 cm3

6. Other Common Regular Solids
pyramid
cylinder
cone

7. Finding the Volume of a Liquid
you can find the volume of a liquid by pouring it into a measuring cylinder or measuring cup
read the volume from the scale by keeping your eye at the level of the water and reading the lower level of the water (called the meniscus)

8. Finding the Volume of a Liquid
it is important that the measuring cylinder is on a flat, level surface

9. Finding the Volume of an Irregular Solid
irregular solid – an object that does not have straight edges or set angles
example: stone

10. Finding the Volume of an Irregular Solid
we can find the volume of an irregular solid by using our knowledge of volume of a liquid
first, place enough water in a graduated cylinder to cover the object and make a reading of the volume
next, place the object in the cylinder
read the new level of the water
the volume of the object by subtracting the first volume reading from the second volume reading

11. Finding the Volume of an Irregular Solid
example:
first reading: 200 ml
second reading: 260 ml
volume = second reading – first reading
volume = 260 ml – 200 ml
volume = 60 ml

12. What you have learned
Copy and complete these sentences using these key words (cubic centimetre, cubic metre, irregular, millilitres, regular, volume):
An object’s is the amount of space it fills
up. Two units of volume are
and Liquid volumes are often
measured in litres or The volume of a
solid is found by multiplying its height by
the length by the width. The volume of an
solid can be found by measuring the volume of
water it displaces.