Measurement · Mathematics · Class 3

This topic comes from GayaGnan's Class 3 catalog. It is generic, not an official board syllabus: check your board's book for the exact chapter.

1 ✨ Spark

Your hand span and your teacher's hand span are different. So how can everyone measure a table and get the same answer?

Think about this for a moment before you start.

Turn the scene, tap the objects and answer. Easy, Medium and Challenge are the three checkpoints.

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We use standard units so everyone gets the same answer. Length is measured in centimetres (cm) and metres (m): 100 cm = 1 m.

Weight is measured in grams (g) and kilograms (kg): 1000 g = 1 kg. A balance is level when both sides weigh the same.

Liquids are measured in millilitres (mL) and litres (L): 1000 mL = 1 L. Always start a ruler measurement from 0.

🇮🇳 Example from India

At a vegetable market, the seller balances 2 kg of potatoes against a 2 kg weight, and milk is sold in 500 mL packets: two packets make 1 litre.

⚠️ Common mistake

✗ I can start measuring from the 1 on the ruler.
✓ Start from 0. If you start at 1, your answer is 1 cm too long.

Play Medium and Challenge in the 3D scene. The bars show how many you got right the first time.

Try this at home or at school, then check the suggested answer.

Scenario You want to buy ribbon to go around a gift box. How will you find how much to ask for?

Show a suggested answer

Measure around the box with a string, then measure the string on a ruler from 0 in cm and add a little extra for the bow.

🧪 Try this activity

Measure 3 things at home with a ruler in cm. Find something that weighs about 1 kg, and count how many glasses of water fill a 1-litre bottle.

Think, then answer in your own words. Your notes stay on this device.

Observation In the 3D scene, the scale is balanced. What does that tell you about the two pans?

My answer

Show a suggested answer

Both pans hold the same weight, so the bag of rice weighs the same as the weights added together.

Explain / create Explain to a friend why we measure from the 0 mark, using a pencil and a ruler.

My answer

Show a suggested answer

Put the pencil end at 0: the tip shows the true length. Starting at 1 adds an extra centimetre, so the answer would be wrong.