Sorting and Making Groups

Active sorting engages children’s natural curiosity and supports their development of early mathematical thinking through hands-on play. When students physically move objects into groups, they strengthen observation skills, build vocabulary, and begin to understand abstract concepts like quantity and classification in a concrete way.

• Senior Infants
• Foundations of Mathematical Thinking
• 4 activities
• 20 min–35 min

Learning Objectives

1. Classify a set of objects into distinct groups based on a single attribute, such as color or shape.
2. Compare the number of objects in two different groups, identifying which group has more or fewer items.
3. Explain the sorting rule used to create specific groups of objects.
4. Demonstrate at least two different ways to sort the same collection of objects.

Experiential Learning

⏱ 30 min·Small Groups

Sorting Tray Challenge: Colours First

Provide trays with mixed buttons or blocks in various colours. Ask children to sort by colour, count each group, and label with numerals. Then challenge them to resorted by size. Circulate to prompt comparisons like 'Which group has more?'

Prepare & details

Can you sort these shapes by colour — how many groups do you have?

Facilitation Tip: During Sorting Tray Challenge: Colours First, model sorting aloud, naming each colour as you place items in the tray to build oral language.

Setup: Varies; may include outdoor space, lab, or community setting

Materials: Experience setup materials, Reflection journal with prompts, Observation worksheet, Connection-to-content framework

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

Experiential Learning

⏱ 25 min·Pairs

Partner Sort Relay: Shape Switch

Pairs sort attribute blocks by shape into hoops, then switch to sorting by colour. One child sorts while the partner counts and compares groups. Switch roles halfway and discuss new groupings found.

Prepare & details

Which group has more — the red ones or the blue ones?

Facilitation Tip: During Partner Sort Relay: Shape Switch, rotate partners after each round to encourage different perspectives and shared decision-making.

Setup: Varies; may include outdoor space, lab, or community setting

Materials: Experience setup materials, Reflection journal with prompts, Observation worksheet, Connection-to-content framework

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

Experiential Learning

⏱ 35 min·Whole Class

Whole Class Object Hunt: Multiple Ways

Children collect classroom items like pencils or toys. As a class, sort first by colour on the floor, count and compare. Erase and resort by length or type, voting on which way works best.

Prepare & details

Can you find another way to sort these objects?

Facilitation Tip: During Whole Class Object Hunt: Multiple Ways, display sorted groups on the board and invite students to physically move items between groups to show alternative sorting.

Setup: Varies; may include outdoor space, lab, or community setting

Materials: Experience setup materials, Reflection journal with prompts, Observation worksheet, Connection-to-content framework

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

Experiential Learning

⏱ 20 min·Individual

Individual Mat Sort: Personal Collections

Give each child a mat and small collection of shells or leaves. They sort independently by one attribute, draw their groups, then share one alternative sort with a neighbour.

Prepare & details

Can you sort these shapes by colour — how many groups do you have?

Facilitation Tip: During Individual Mat Sort: Personal Collections, provide sentence starters like ‘I sorted by ____ because ____.’ to scaffold explanations.

Setup: Varies; may include outdoor space, lab, or community setting

Materials: Experience setup materials, Reflection journal with prompts, Observation worksheet, Connection-to-content framework

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

Teaching This Topic

Teach sorting by starting with clear, limited attributes to avoid cognitive overload, then gradually introduce complexity. Use real, familiar objects rather than pictures to ground the experience in tangible learning. Encourage peer talk to strengthen reasoning skills, as explaining choices deepens understanding more than teacher-led instruction alone. Avoid rushing to abstract symbols; let children verbalize and manipulate before connecting to written recording.

What to Expect

By the end of these activities, students will confidently sort objects using at least one attribute, count and compare group sizes, and explain their sorting choices using clear language. They will also demonstrate flexibility by attempting alternative groupings when prompted.

Watch Out for These Misconceptions

Common Misconception

During Sorting Tray Challenge: Colours First, watch for children who insist on sorting by one colour only and refuse to group others that don’t match.

What to Teach Instead

Prompt them to find all items that match their chosen colour first, then ask, ‘What else do you notice about these items? Can we sort them by something else?’

Common Misconception

During Partner Sort Relay: Shape Switch, watch for students who assume the group with more space between items has more objects.

What to Teach Instead

Ask them to line up items from each group side-by-side on the mat and count again to verify the quantity.

Common Misconception

During Individual Mat Sort: Personal Collections, watch for students who group items without a consistent rule, such as mixing size and colour freely.

What to Teach Instead

Ask them to explain their rule aloud. If unclear, say, ‘Tell me why this big red block and this small blue block are together.’ Guide them to restate a clear attribute.

Assessment Ideas

Quick Check

After Sorting Tray Challenge: Colours First, give each student a small collection of mixed objects and ask them to sort into two colour groups. Observe whether they can create two distinct groups and ask, ‘How many in this group? How many in the other? Which has more?’

Discussion Prompt

During Whole Class Object Hunt: Multiple Ways, present a collection already sorted by shape. Ask students to explain the sorting rule and invite them to suggest another way to group the same items. Listen for clear articulation of criteria.

Exit Ticket

After Individual Mat Sort: Personal Collections, give each child a bag of 5-6 mixed objects and ask them to sort by size. Have them draw and label their groups on paper to show understanding of quantity and attribute choice.

Extensions & Scaffolding

• Challenge: After Partner Sort Relay, ask students to sort the same set of shapes by two attributes at once (e.g., red circles and blue squares).
• Scaffolding: Provide a visual sorting mat with labeled sections during Individual Mat Sort for students who need support in choosing an attribute.
• Deeper: Extend Whole Class Object Hunt by asking students to predict how many items will be in each group before sorting, then compare predictions to actual counts.

Key Vocabulary

Sort	To arrange items into groups based on shared characteristics or attributes.
Group	A collection of items that have been put together because they are alike in some way.
Attribute	A characteristic or feature of an object, such as its color, shape, or size.
Compare	To look at two or more groups and decide which has more, fewer, or the same amount.