Mathematics · Senior Infants

Active learning ideas

Heavy and Light , Weighing

Active learning works well for this topic because children need to physically experience mass through touch and sight before they can understand abstract concepts like balance and comparison. When they lift objects and see scales tip, they connect concrete experiences to the language of heavier and lighter in a way that static pictures or verbal explanations cannot match.

• NCCA Curriculum Specifications
• NCCA: Junior Cycle - Measurement - M.3

• 15–30 min
• Pairs → Whole Class
• 4 activities

Activity 01

• Experiential Learning
• 25 min · Pairs

Pairs: Scale Prediction Challenges

Pair children with a balance scale and sets of three objects, like eraser, book, and block. They predict and test which is heaviest or lightest, then swap sets. Discuss results as a class.

Which object feels heavier , the book or the pencil case?

Facilitation Tip

During Scale Prediction Challenges, circulate with a notepad to jot down predictions before testing to encourage children to think before they act.

What to look for

Present two classroom objects (e.g., a block and a crayon). Ask students to hold one in each hand and state which is heavier. Then, ask them to explain their choice using the word 'heavier' or 'lighter'.

• Apply
• Analyze
• Evaluate
• Self-Awareness
• Self-Management
• Social Awareness

Activity 02

• Experiential Learning
• 30 min · Small Groups

Small Groups: Object Ordering Line-Up

Give each group 8-10 mixed objects. Children feel and compare to line them from lightest to heaviest. Groups share their orders and test tricky pairs on scales.

Can you balance the scales , what do you need to add?

Facilitation Tip

For Object Ordering Line-Up, provide a mix of textured items to help tactile learners make connections between feel and weight.

What to look for

Provide students with three small objects (e.g., a feather, a small toy car, a rock). Ask them to draw the objects in order from lightest to heaviest on a piece of paper and label them 'lightest', 'middle', and 'heaviest'.

• Apply
• Analyze
• Evaluate
• Self-Awareness
• Self-Management
• Social Awareness

Activity 03

• Experiential Learning
• 20 min · Whole Class

Whole Class: Heavy or Light Hunt

Call out categories like soft toys or metal items. Children hunt one heavy and one light example, bring to front, and class votes before scale testing.

Put these objects in order from lightest to heaviest.

Facilitation Tip

In the Heavy or Light Hunt, give each pair a small basket to collect objects, which keeps the activity focused and manageable.

What to look for

Place a balance scale in front of the class with one object on each side. Ask: 'What do you predict will happen when I put this book on one side and this pencil case on the other?' After the demonstration, ask: 'Why did the scale tip this way? How could we make it balance?'

• Apply
• Analyze
• Evaluate
• Self-Awareness
• Self-Management
• Social Awareness

Activity 04

• Experiential Learning
• 15 min · Individual

Individual: Hand Feel Sort

Provide trays with 6 paired objects. Children sort into heavier/lighter piles using hands only, then verify with partner scales.

Which object feels heavier , the book or the pencil case?

Facilitation Tip

For Hand Feel Sort, use objects of similar sizes but different weights so children focus on mass rather than visual clues.

What to look for

Present two classroom objects (e.g., a block and a crayon). Ask students to hold one in each hand and state which is heavier. Then, ask them to explain their choice using the word 'heavier' or 'lighter'.

• Apply
• Analyze
• Evaluate
• Self-Awareness
• Self-Management
• Social Awareness

A few notes on teaching this unit

Start with what children already know by asking them to lift familiar objects and describe how they feel. Avoid explaining too soon; let them discover through guided exploration. Use consistent language like 'this side is lower, so it is heavier' to build accurate vocabulary. Research suggests that repeated hands-on experiences over time solidify understanding better than one-off demonstrations. Watch for children who rely on visual size and gently redirect their attention to the feel of the objects.

Successful learning looks like children confidently comparing objects by mass, using accurate language such as heavier, lighter, and balances. They should demonstrate this through predictions, testing, and ordering, showing they understand that size does not always match mass and that balance scales provide a way to test hypotheses.

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Watch Out for These Misconceptions

• During Scale Prediction Challenges, watch for children assuming larger objects are always heavier.

  Bring out a large, lightweight balloon and a small, heavy stone. Have children lift both and explain that their hands feel different masses even though the balloon is bigger. Use the balance scale to confirm the stone is heavier, reinforcing that size does not determine weight.

• During Object Ordering Line-Up, watch for children believing scales balance only if objects look identical.

  Provide two identical-looking containers, one filled with sand and the other with feathers. Ask children to predict which will tip the scale. After testing, discuss how the hidden sand makes the container heavier, showing that looks can be deceiving.

• During Heavy or Light Hunt, watch for children linking mass directly to speed when sinking in water.

  Provide a cotton ball and a coin for testing in water. Ask children to predict which will sink faster and then observe together. Discuss how the coin is heavier but the cotton ball floats because of its shape and material, separating the ideas of mass and buoyancy.

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Methods used in this brief

• Experiential Learning