Weight and Capacity
Class 5 · Mathematics
6 ideas in Class 5 Mathematics, explained in plain words, with games and quizzes to practise.
Reading Weighing Scales
Part of: Measuring Weight
A weighing scale shows how heavy something is. Different scales show weight in different ways. Some scales have a needle that points to a number, and you read where the needle stops. Some scales show numbers on a screen. To read a scale, first find where the needle is pointing, then look at the numbers around it to find the exact weight.
Why it matters. Learning to read scales helps children understand how much things weigh and prepares them to use scales for cooking, shopping, or checking their own weight. A scale is a tool they will use all their life.
Try it in two minutes
- Gather a kitchen scale, a weighing machine, or a picture of a scale.
- Point to different numbers on the scale and ask your child to say what weight each one shows.
- Place different objects on the scale (fruit, a toy, a book) and read the weight together.
- Ask: is this heavier or lighter than your guess?
Try at home. Weigh five things in your kitchen and write their weights on a piece of paper.
Converting Between Kilograms and Grams
Part of: Measuring Weight
A kilogram and a gram are both units of weight. A kilogram is much heavier than a gram. In fact, 1 kilogram equals 1000 grams. When you know the relationship, you can change any weight from kilograms to grams or from grams to kilograms. For example, 2 kg is 2 × 1000 = 2000 g. And 5000 g is 5000 ÷ 1000 = 5 kg.
Why it matters. Different things are measured in different units. A grain of rice is in grams, but a bag of rice is in kilograms. Learning to convert helps you understand any weight and compare different measurements.
Try it in two minutes
- Tell your child: 1 kilogram is 1000 grams. Say it together a few times.
- Ask: How many grams are in 2 kilograms? (2 × 1000 = 2000 grams)
- Ask: How many kilograms are in 4000 grams? (4000 ÷ 1000 = 4 kilograms)
- Practice with more numbers: 3 kg, 5 kg, 7000 g, 9000 g.
Try at home. Write these on paper: 1 kg, 2 kg, 3000 g, 7000 g. Ask your child to write how many grams are in each kg, and how many kg are in each g amount.
Comparing Weights
Part of: Measuring Weight
When you have two weights, you can compare them to see which is more, which is less, or if they are the same. You use three comparison symbols. The symbol that looks like a mouth always opens toward the bigger number. For example, 5 kg is greater than 4 kg.
Why it matters. Comparing weights helps you decide if you can carry two bags together, or if one is heavier than the other. It is useful for shopping, cooking, and moving things.
Try it in two minutes
- Hold two objects of different weight (like a book and an apple). Ask: which is heavier?
- Write two weights on paper: 3 kg and 3000 g. Ask: are they the same weight?
- Write more pairs: 2 kg vs 2500 g, 1 kg 200 g vs 1200 g. Discuss which is heavier.
- Write the correct symbol (<, =, or >) between each pair.
Try at home. Write pairs of weights and ask your child to put the correct symbol between them. Make some pairs where the amounts are equal, some where the first is bigger, and some where the second is bigger.
Understanding Milligrams
Part of: Measuring Weight
A milligram is a very small unit of weight. It is so small that 1000 milligrams make just 1 gram. Milligrams are used to weigh things that are very light, like the ingredients in medicine, spices, or gold ornaments. Think of it this way: if a grain of rice weighs about 20 mg, then 50 grains of rice weigh about 1 gram.
Why it matters. Many important things are measured in milligrams: medicine doses, vitamin pills, gold weights. Understanding milligrams helps you read medicine labels and understand very small weights.
Try it in two minutes
- Tell your child: 1 gram is 1000 milligrams. This is a very small amount.
- Show a small object like a grain of rice or a salt crystal. Say: this weighs just a few milligrams.
- Ask: if 1 gram is 1000 mg, how many mg are in 2 grams? (2000 mg)
- Ask: how many grams are in 5000 mg? (5 grams)
Try at home. Look at a medicine bottle or vitamin label with your child and read the milligram amounts listed. Discuss why such small amounts are used.
Understanding Litres and Millilitres
Part of: Measuring Capacity
Capacity is how much a container can hold. We measure capacity in litres and millilitres. A litre is a large unit, and a millilitre is a small unit. Just like with weight, 1 litre equals 1000 millilitres. A glass of water is about 200 ml, and a bucket might hold 10 litres. Learning these measurements helps you understand how much milk, juice or water you need.
Why it matters. Capacity is used every day: pouring milk for tea, filling a water bottle, buying juice. Understanding capacity helps you measure liquids correctly and avoid waste.
Try it in two minutes
- Show a one-litre container and a cup. Say: this cup is about 250 ml, and this large container is 1 litre or 1000 ml.
- Fill the cup with water and ask: how many cups like this would fill the litre container? (About 4 cups)
- Ask: if 1 litre is 1000 ml, how many ml are in 2 litres? (2000 ml)
- Ask: how many litres are in 5000 ml? (5 litres)
Try at home. Gather different bottles and containers at home. Label them with their capacity if marked, or estimate the capacity with your child.
Adding and Subtracting Capacities
Part of: Measuring Capacity
When you add or subtract capacities, you work with litres and millilitres just like you work with kg and g. You can add them separately (litres together, millilitres together), and then combine the result. Or you can convert everything to millilitres, do the operation, and convert back. For example, 3 l 500 ml + 2 l 600 ml can be done as: 3 l + 2 l = 5 l, and 500 ml + 600 ml = 1100 ml = 1 l 100 ml. So the total is 5 l + 1 l 100 ml = 6 l 100 ml.
Why it matters. Adding and subtracting capacities is useful when mixing liquids, dividing juice among people, or planning how much liquid you need for cooking or cleaning.
Try it in two minutes
- Say: you have a bottle with 2 l of milk and another with 1 l 500 ml. Together, how much?
- Work it out: 2 l + 1 l = 3 l, and 0 ml + 500 ml = 500 ml. Total is 3 l 500 ml.
- Say: if you use 1 l 200 ml from a 5 l tank, how much is left?
- Work it out: 5 l 0 ml - 1 l 200 ml = 3 l 800 ml.
Try at home. Create problems with household items. Ask: if you mix 2 l of juice with 1 l 500 ml of water, how much do you have? Or: if you have 4 l of water and use 1 l 750 ml, how much is left?
What your child will practise
- Adding and Subtracting Capacities: Ocean Quick Fire (Quick Fire)
- Comparing Weights: Ocean Quest (Collect the Answer)
- Converting Between Kilograms and Grams: Jungle Quest (Flip and Match)
- Reading Weighing Scales: Ocean Puzzle (Clue Puzzle)
- Understanding Litres and Millilitres: Castle Sort (Sort It Out)
- Quiz: Adding and Subtracting Capacities (8 questions)
- Quiz: Comparing Weights (8 questions)
- Quiz: Converting Between Kilograms and Grams (8 questions)
- Quiz: Reading Weighing Scales (8 questions)