Learning Objectives
- Measure capacity using litres and millilitres
- Convert between litres and millilitres
- Compare the capacity of different containers
- Solve word problems on capacity
Key Concepts
Measuring Capacity
Capacity is how much liquid a container can hold. We measure capacity in litres (L) and millilitres (mL). A litre is used for bigger amounts, like a bottle of water. A millilitre is used for smaller amounts, like a dose of medicine. 1 litre = 1000 millilitres.
Converting Units
To convert litres to millilitres, multiply by 1000. So 3 L = 3000 mL. To convert millilitres to litres, divide by 1000. So 2500 mL = 2 L 500 mL. When adding or subtracting capacities, make sure both are in the same unit first.
Comparing Containers
To compare how much two containers hold, fill one with water and pour it into the other. If a jug fills 4 glasses and a pot fills 6 glasses, the pot holds more than the jug. You can also use a measuring cup with markings to measure the exact capacity of any container.
Word Problems on Capacity
A bucket holds 10 litres of water. If you fill 3 buckets, you have 10 x 3 = 30 litres. If you use 12 litres for washing clothes and 8 litres for cleaning the floor, you use 12 + 8 = 20 litres. You still have 30 - 20 = 10 litres left. Always think about what the question is asking!
Important Terms
- Capacity: The amount of liquid a container can hold
- Litre (L): A unit for measuring larger amounts of liquid
- Millilitre (mL): A unit for measuring smaller amounts of liquid
- Measuring Cup: A cup with markings to measure liquids accurately
- Volume: The amount of space a liquid takes up
Quick Revision
- 1 litre = 1000 millilitres
- Half a litre = 500 mL, Quarter litre = 250 mL
- Convert to the same unit before adding or subtracting
- L to mL: multiply by 1000; mL to L: divide by 1000
- Common capacities: teaspoon ~ 5 mL, glass ~ 250 mL, bottle ~ 1 L
- Use a measuring cup for accurate measurement