Foundations of Mathematical Thinking · Senior Infants

Active learning ideas

Biggest and Smallest in a Group

Active learning works for this topic because young children build spatial reasoning through touch and movement. When they physically stack, sort, and compare, abstract ideas like 'biggest' and 'smallest' become concrete. These hands-on experiences create mental models that future math skills will rely on.

• NCCA Curriculum Specifications
• NCCA: Junior Cycle - Statistics and Probability - SP.3

• 25–40 min
• Pairs → Whole Class
• 4 activities

Activity 01

• Collaborative Problem-Solving
• 30 min · Pairs

Tower Challenge: Tallest and Shortest Towers

Children work in pairs to build towers with 10-15 linking cubes, then measure heights using non-standard units like hand spans. Pairs line up towers and identify the tallest and shortest, discussing why one stands out. Record range as tallest minus shortest on a class chart.

Which is the tallest tower , can you show me?

Facilitation Tip

During Tower Challenge, circulate and ask each pair to explain how they know one tower is taller than the other.

What to look for

Present a tray of mixed-size blocks. Ask students to point to the 'biggest block' and then the 'smallest block'. Observe if they can accurately identify these items.

• Apply
• Analyze
• Evaluate
• Create
• Relationship Skills
• Decision-Making
• Self-Management

Activity 02

• Collaborative Problem-Solving
• 25 min · individual then pairs

Stick Sort: Length Order

Collect sticks from the school yard, sort them individually from shortest to longest on a mat. Compare with a partner to find group biggest and smallest, noting any outlier sticks. Share findings whole class, calculating rough range by laying end-to-end.

Can you find the smallest number in this row?

Facilitation Tip

For Stick Sort, model lining up sticks on a flat surface so students see the difference in length clearly.

What to look for

Give each student a small bag with 3-4 different sized objects (e.g., buttons, pom-poms). Ask them to draw the objects in order from smallest to biggest on a piece of paper and label the smallest and biggest.

• Apply
• Analyze
• Evaluate
• Create
• Relationship Skills
• Decision-Making
• Self-Management

Activity 03

• Collaborative Problem-Solving
• 35 min · Small Groups

Toy Mass Hunt: Heaviest and Lightest

Provide small groups with 8-10 toys varying in weight. Children order by lifting and comparing feel, identify heaviest and lightest as outliers. Discuss impact if outlier is removed, using a balance scale for verification.

Put these objects in order from smallest to biggest.

Facilitation Tip

In Toy Mass Hunt, let students hold two objects at a time to feel the difference before placing them on the balance scale.

What to look for

Show a group of objects where one is significantly larger or smaller than the rest. Ask: 'If we were talking about how tall these are, what is the tallest? What is the shortest? Does this very tall one make the others look smaller? How?'

• Apply
• Analyze
• Evaluate
• Create
• Relationship Skills
• Decision-Making
• Self-Management

Activity 04

• Collaborative Problem-Solving
• 40 min · Whole Class

Class Height Line-Up

Measure whole class heights with a paper chain or string marks on the wall. Children order themselves tallest to shortest, spot the extremes, and note range in steps. Discuss how one child's growth spurt acts as an outlier.

Which is the tallest tower , can you show me?

Facilitation Tip

During Class Height Line-Up, have students stand back to see the full line and discuss who is in the middle.

What to look for

Present a tray of mixed-size blocks. Ask students to point to the 'biggest block' and then the 'smallest block'. Observe if they can accurately identify these items.

• Apply
• Analyze
• Evaluate
• Create
• Relationship Skills
• Decision-Making
• Self-Management

A few notes on teaching this unit

Teachers should model precise language during activities, such as 'This tower is three blocks taller than that one' instead of 'This one is bigger'. Avoid rushing to abstract symbols; let children experience the range first through physical comparison. Research shows that when students verbalize their reasoning while sorting, their understanding deepens. Keep groups small so every child participates and misconceptions surface quickly.

Successful learning looks like children confidently ordering objects by size, using comparative language like 'taller than' or 'lighter than'. They should explain their choices with reasoning and adjust their sorting when prompted. Partner talk and peer feedback help solidify these skills.

---

Watch Out for These Misconceptions

• During Stick Sort, watch for children picking the median stick as the smallest or biggest instead of the actual extremes.

  Ask students to point to the shortest stick first, then the longest. Have them physically place these two sticks at opposite ends of the table to create a visual boundary for comparison.

• During Toy Mass Hunt, watch for students ignoring the heaviest toy when determining the range of weights.

  Ask them to hold the heaviest and lightest toys together and feel the difference. Then prompt: 'If we remove this very heavy one, does the heaviest still feel heavy? Why or why not?'

• During Class Height Line-Up, watch for students assuming the tallest child is also the heaviest or oldest.

  Point to two children in line and ask: 'Is the tallest child always the one who can lift the heaviest object? Try it with these cubes.' Let them test and discuss the difference between height and mass.

---

Methods used in this brief

• Collaborative Problem-Solving