Mathematics · Class 3

Active learning ideas

Measurement of Weight: Non-Standard Units

Active learning helps students grasp that weight is not just about how big something looks. When children handle objects and measure them with non-standard units, they directly experience how mass, not size alone, determines balance. This hands-on approach makes abstract ideas concrete and memorable for young learners.

• CBSE Learning Outcomes
• NCERT Class 3, Chapter 8: Who is Heavier? - Guessing and telling weights.
• CBSE Syllabus Class 3: Measurement - Compares weights of objects using a simple balance.
• NEP 2020: Foundational Numeracy - Develops an understanding of weight through comparison.

• 25–45 min
• Pairs → Whole Class
• 4 activities

Activity 01

• Think-Pair-Share
• 35 min · Pairs

DIY Balance Scale Construction

Provide rulers, strings, and plastic cups for students to build balances. In pairs, they test objects like erasers and chalk pieces, noting how many marbles balance each. Pairs share results and discuss surprises.

Explain why non-standard units can be inconsistent for measuring weight.

Facilitation Tip

During DIY Balance Scale Construction, remind groups to tie the string tightly so the ruler stays balanced in the middle.

What to look for

Present students with two different objects (e.g., a small stone and a large eraser). Ask them to predict which is heavier. Then, provide them with a simple balance scale and a set of non-standard units (like beads). Have them measure and record how many beads balance each object, and then state which object is heavier based on their findings.

• Understand
• Apply
• Analyze
• Self-Awareness
• Relationship Skills

Activity 02

• Think-Pair-Share
• 45 min · Small Groups

Object Weighing Stations

Set up stations with non-standard units: blocks for books, marbles for fruits, pencils for bags. Small groups rotate, measure three objects per station, and record counts on charts. Conclude with class comparison.

Construct a balance scale to compare the weight of two objects.

Facilitation Tip

At Object Weighing Stations, circulate and ask guiding questions like, 'Why do you think the pebble needed more beads than the eraser?'

What to look for

Ask students: 'Imagine you are measuring the weight of a book using marbles, and your friend measures the same book using pebbles. Will you get the same number of marbles as your friend gets pebbles? Why or why not?' Listen for explanations about the different sizes and weights of marbles versus pebbles.

• Understand
• Apply
• Analyze
• Self-Awareness
• Relationship Skills

Activity 03

• Think-Pair-Share
• 30 min · Small Groups

Weight Sorting Relay

Divide class into teams. Each team sorts classroom items into 'light', 'medium', and 'heavy' piles using hand balances and blocks. Teams verify by balancing against standards and explain choices.

Analyze real-world situations where comparing weights is essential.

Facilitation Tip

For Weight Sorting Relay, pair students so they can discuss their reasoning before placing objects in order.

What to look for

Give each student a small drawing of a balance scale with two different objects on each side (e.g., 3 blocks on one side, 1 toy car on the other). Ask them to circle the side that is heavier and write one sentence explaining their choice.

• Understand
• Apply
• Analyze
• Self-Awareness
• Relationship Skills

Activity 04

• Think-Pair-Share
• 25 min · Individual

Real-Life Weighing Hunt

Students hunt for pairs of objects around the classroom that balance with the same number of erasers. Individually record pairs and units used, then verify in whole class discussion.

Explain why non-standard units can be inconsistent for measuring weight.

Facilitation Tip

During Real-Life Weighing Hunt, provide a checklist to keep students focused on finding objects of varied weights.

What to look for

Present students with two different objects (e.g., a small stone and a large eraser). Ask them to predict which is heavier. Then, provide them with a simple balance scale and a set of non-standard units (like beads). Have them measure and record how many beads balance each object, and then state which object is heavier based on their findings.

• Understand
• Apply
• Analyze
• Self-Awareness
• Relationship Skills

A few notes on teaching this unit

Teachers should let students explore first before explaining, as this builds curiosity and ownership of learning. Avoid rushing to correct misconceptions; instead, use the activities as evidence to guide discussions. Research shows that peer collaboration and immediate feedback during hands-on tasks strengthen conceptual understanding.

By the end of these activities, students will confidently compare weights using non-standard units and explain why a small heavy object can outweigh a large light one. They will also recognise that measurement results depend on the choice of unit and discuss how standardisation helps.

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Watch Out for These Misconceptions

• During DIY Balance Scale Construction, watch for students who assume the larger object is heavier simply because it takes up more space.

  Ask them to balance a small stone against a large sponge using their scale. Then, have them replace the sponge with a smaller stone of the same material to observe how weight shifts with mass.

• During Object Weighing Stations, watch for students who believe non-standard units always give identical results for the same object.

  Have them measure the same book using marbles and then pebbles. Guide them to compare counts and discuss why differences occur, linking this to the need for standard units.

• During Real-Life Weighing Hunt, watch for students who confuse weight with size or volume.

  Provide a feather and a pebble, and ask them to predict which will balance more marbles. After measuring, have them describe what the activity revealed about weight versus appearance.

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Methods used in this brief

• Think-Pair-Share