Mathematics · Year 1

Active learning ideas

Measuring Length with Non-Standard Units

Active learning helps students grasp mass and weight concepts by moving beyond abstract comparisons to hands-on experiences. When children physically compare objects using balance scales, they develop accurate intuition about heaviness and lightness in ways that static discussions cannot. This tactile approach reduces reliance on visual cues alone, which can be misleading for young learners.

• National Curriculum Attainment Targets
• KS1: Mathematics - Measurement

• 10–20 min
• Pairs → Whole Class
• 3 activities

Activity 01

• Inquiry Circle
• 20 min · Small Groups

Inquiry Circle: Heavy or Light Hunt

Groups are given a 'mystery object' and must find three things in the room that are heavier and three that are lighter, using balance scales to prove their findings to the class.

Explain why using paper clips is a fair way to measure length.

Facilitation Tip

During the Heavy or Light Hunt, circulate to listen for students using comparative language like 'heavier than' or 'lighter than' as they justify their choices.

What to look for

Provide students with a collection of classroom objects (e.g., pencil, book, glue stick) and a pile of paper clips. Ask them to measure the length of each object using the paper clips and record their findings. Observe if they consistently use the paper clips end-to-end without gaps or overlaps.

• Analyze
• Evaluate
• Create
• Self-Management
• Self-Awareness

Activity 02

• Think-Pair-Share
• 10 min · Pairs

Think-Pair-Share: The Size Trap

Show a large sponge and a small lead weight (or heavy stone). Pairs must predict which is heavier, then use the scales to check. They discuss why the 'bigger' item isn't always the 'heavier' one.

Predict what would happen if we used different sized hands to measure the same table.

Facilitation Tip

For The Size Trap, provide a variety of objects with similar sizes but different weights to challenge assumptions about mass.

What to look for

Present two scenarios: one where a table is measured with small blocks and another where the same table is measured with large blocks. Ask students: 'Which measurement will have more blocks? Why?' Guide them to explain why using the same size unit is important for fair comparison.

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

Activity 03

• Stations Rotation
• 20 min · Small Groups

Stations Rotation: Weight Matching

Set up stations where students must find how many 'units' (e.g., wooden blocks) it takes to balance a specific toy. They rotate to see how different toys require different amounts of blocks to reach a balance.

Design a way to measure the length of the classroom using only your feet.

Facilitation Tip

Set up the Weight Matching stations with clear labels and a timer to keep groups focused on comparing objects accurately.

What to look for

Give each student a picture of a classroom object (e.g., a whiteboard). Ask them to draw how they would measure its length using their feet and write one sentence explaining their method. Prompt: 'How many of your feet long is the whiteboard?'

• Remember
• Understand
• Apply
• Analyze
• Self-Management
• Relationship Skills

A few notes on teaching this unit

Teach this topic by starting with concrete comparisons before introducing tools like balance scales. Avoid using terms like 'big' or 'small' to describe weight, as these reinforce misconceptions. Research shows that young children benefit from repeated exposure to hands-on activities where they can test their ideas and receive immediate feedback. Encourage them to verbalize their observations to embed the correct vocabulary.

Successful learning looks like students using balance scales correctly to compare objects, explaining their reasoning with precise vocabulary, and recognizing that size does not always determine weight. They should also adjust their measurements when using non-standard units, ensuring consistency in their methods.

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Watch Out for These Misconceptions

• During the Heavy or Light Hunt, watch for students assuming a larger object is always heavier.

  Provide a large empty box and a small metal ball at one station. Ask students to predict which is heavier, then use the balance scale to test their hypothesis, highlighting that material matters more than size.

• During the Station Rotation: Weight Matching, students may think the side that rises is the heavier one.

  Remind students to think of the balance scale like a seesaw. Show them that the side holding the heavier object will tilt downward, just as a heavier person on a seesaw sits lower to the ground.

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Methods used in this brief

• Inquiry Circle
• Think-Pair-Share
• Stations Rotation