⚖️ Weight and Capacity
Class 3 Maths · Unit 10 of 12 · about 110 minutes
Compares and measures how heavy things are using a simple balance and standard weights (grams and kilograms), and how much containers hold using litres and millilitres informally. Children estimate, read labels, learn 1 kg = 1000 g and 1 L = 1000 mL, and solve simple weight and capacity problems in whole units.
What your child will learn
- Students will be able to compare weights using a two-pan balance and order three objects from lightest to heaviest.
- Students will be able to estimate and measure weight in grams and kilograms, choose the sensible unit, and know 1 kg = 1000 g.
- Students will be able to compare and measure capacity using litres and millilitres, choose the sensible unit, and know 1 L = 1000 mL.
- Students will be able to solve simple word problems adding or subtracting weights or capacities in the same unit.
Lessons in this unit
- Heavier or lighter: using a balance: Read a two-pan balance (the lower pan is heavier), compare two objects, and order three objects by weight.
- Grams and kilograms: Introduce the kilogram and gram with real packets, estimate weights of everyday objects, choose g or kg, and learn 1 kg = 1000 g, 500 g = half a kilogram.
- Litres and millilitres: Compare how much containers hold by pouring, introduce the litre with a 1 L bottle, read capacities on packets (200 mL, 500 mL, 1 L, 2 L), choose L or mL, and learn 1 L = 1000 mL.
- Weight and capacity problems: Add and subtract weights or capacities in the same unit to find totals and what is left, and decide whether a container or bag is big enough.
Key words
- weight / heavy / light
- How much something pulls down when you lift it.
- gram (g)
- A small unit of weight; a paper clip weighs about 1 g.
- kilogram (kg)
- A big unit of weight; a big packet of rice or 5 apples. 1 kg = 1000 g.
- balance
- A scale with two pans; the heavier side goes down.
- capacity
- How much a container can hold.
- litre (L) / millilitre (mL)
- Units for liquids. A big water bottle is 1 L; a spoon holds about 5 mL. 1 L = 1000 mL.
Help your child at home
What to watch for
- Bigger objects are always heavier.
- Help: A big balloon is lighter than a small stone. Weight is not size; use the balance.
- 1 kg = 100 g.
- Help: It takes ten 100 g packets to balance 1 kg. 1 kg = 1000 g.
- The taller container always holds more.
- Help: Pour to check. A short wide dabba can hold more than a tall thin glass.
- 1 kg + 500 g = 501 g or 501 kg.
- Help: Change 1 kg to 1000 g first: 1000 g + 500 g = 1500 g, which is 1 kg 500 g.
Try this at home
- Read a balance with an apple and a ball
- Balance 1 kg with two 500 g
- Fill a jug with cups
- 250 g + 500 g
Quick questions to ask aloud
- On a balance, the pan with the mango goes down and the pan with the biscuit goes up. Which is heavier? (The mango / The biscuit / They weigh the same)
Show answer
Heavy things pull the pan down. The mango's pan is down, so the mango is heavier. - How many grams are in 1 kilogram?
Show answer
1 kg = 1000 g. Ten packets of 100 g make 1 kg. - Which unit is best for the medicine in a spoon? (Millilitres / Litres / Kilograms)
Show answer
A spoon holds about 5 mL. Millilitres are for small amounts of liquid.
Frequently asked questions
What will my child learn in "Weight and Capacity" (Class 3 Maths)?
Your child will be able to: compare weights using a two-pan balance and order three objects from lightest to heaviest.; estimate and measure weight in grams and kilograms, choose the sensible unit, and know 1 kg = 1000 g.; compare and measure capacity using litres and millilitres, choose the sensible unit, and know 1 L = 1000 mL.; solve simple word problems adding or subtracting weights or capacities in the same unit..
How does MangoMindz teach "Weight and Capacity"?
In 4 short parts (Heavier or lighter: using a balance, Grams and kilograms, Litres and millilitres, Weight and capacity problems). Each part has a picture-based lesson read aloud by Mango Teacher, a quick check, and a quiz built from common mistakes children make, with Mango, a study buddy, for questions.
How long does "Weight and Capacity" take?
About 110 minutes in total, spread over 4 parts of 15–25 minutes each.
How can I help my child with "Weight and Capacity" at home?
Work through a small example together, such as: Read a balance with an apple and a ball; Balance 1 kg with two 500 g. Then ask a quick question aloud: On a balance, the pan with the mango goes down and the pan with the biscuit goes up. Which is heavier? (The mango / The biscuit / They weigh the same)
What mistakes do children often make in "Weight and Capacity"?
Bigger objects are always heavier. Fix: A big balloon is lighter than a small stone. Weight is not size; use the balance. 1 kg = 100 g. Fix: It takes ten 100 g packets to balance 1 kg. 1 kg = 1000 g. The taller container always holds more. Fix: Pour to check. A short wide dabba can hold more than a tall thin glass.
Is "Weight and Capacity" free on MangoMindz?
Yes. Every lesson part and quiz in "Weight and Capacity" is free on MangoMindz, with no ads.