Chapter 2 • AC9M1N02

Year 1 Number Partitioning Activities

Help children develop strong place value skills with engaging Year 1 Number Partitioning activities and printable worksheets aligned to Australian Curriculum AC9M1N02. Students explore part-part-whole relationships, number bonds to 10, tens and ones, and flexible ways to partition one- and two-digit numbers using hands-on materials and visual models.

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About This Year 1 Maths Topic

Partitioning numbers means breaking a number into smaller parts. In Year 1, students learn that the same number can be separated in different ways while the total remains unchanged.

Students build part-part-whole knowledge to 10, identify pairs of numbers that combine to make 10, and use physical and virtual materials to explore number bonds.

They also partition two-digit numbers into tens and ones, such as recognising 35 as 3 tens and 5 ones. Flexible partitioning extends this understanding by showing that 35 can also be represented as 2 tens and 15 ones.

Students record partitions using numerals and explain how the parts combine to make the whole. These activities strengthen place value, mental computation and later addition and subtraction strategies.

These activities support the Australian Curriculum Version 9.0 content descriptor AC9M1N02 and its associated elaborations.

Australian Curriculum Alignment

AC9M1N02

Partition one- and two-digit numbers in different ways using physical and virtual materials, including partitioning two-digit numbers into tens and ones.

AC9M1N02_E1

Build knowledge and understanding of part-part-whole facts to 10 using physical and virtual materials, including ten-frames to identify pairs of numbers that combine to make 10.

AC9M1N02_E2

Use physical and virtual materials to partition numbers into counts of tens and ones; for example, recognise 35 as 3 tens and 5 ones or as 2 tens and 15 ones.

AC9M1N02_E3

Use part-part-whole reasoning and materials to represent numbers such as 24, partition them in different ways and record the partitions using numbers.

Learning Intentions

Students will learn to:

  • identify the whole and its parts;
  • partition numbers to 10 in different ways;
  • find pairs of numbers that combine to make 10;
  • use ten-frames to represent number bonds;
  • partition two-digit numbers into tens and ones;
  • rename one ten as 10 ones;
  • partition the same number in more than one way;
  • record number partitions using numerals;
  • explain how the parts combine to make the whole;
  • use flexible partitioning to support mental calculation.

Student Success Criteria

I can split a number into two parts.

I can find two numbers that make 10.

I can use a ten-frame to show a number bond.

I can identify the whole and the parts.

I can show a two-digit number using tens and ones.

I can rename one ten as 10 ones.

I can partition the same number in different ways.

I can record my partitions using numerals.

I can explain how the parts make the whole.

Key Vocabulary

partition part whole part-part-whole number bond combine split tens ones place value represent rename compose decompose equal total

Teacher Guide

Recommended Materials

  • counters, cubes, buttons or bottle caps;
  • five-frames and ten-frames;
  • part-part-whole mats;
  • number bond templates;
  • base-ten blocks;
  • bundled sticks or popsticks;
  • place value mats;
  • number cards;
  • dice and dominoes;
  • mini whiteboards and markers;
  • digital ten-frames and virtual manipulatives;
  • sorting hoops, cups or trays.

Suggested Teaching Sequence

  1. Begin with small collections and physically split them into two groups.
  2. Introduce part-part-whole language and identify the total as the whole.
  3. Use ten-frames to investigate combinations that make 10.
  4. Record each partition using numerals and simple number sentences.
  5. Build two-digit numbers using tens rods and ones cubes.
  6. Ask students to identify how many tens and ones are shown.
  7. Rename one ten as 10 ones and compare the two representations.
  8. Partition the same two-digit number in several ways.
  9. Encourage students to explain why each representation has the same total.
  10. Apply flexible partitioning to simple mental addition and subtraction problems.

Teacher Questions

  • What is the whole?
  • What are the two parts?
  • How many are in each part?
  • Do the two parts still make the same whole?
  • What pairs of numbers make 10?
  • How does the ten-frame help you see the missing part?
  • How many tens and ones are in this number?
  • Can one ten be renamed as ones?
  • Can you partition this number in another way?
  • How do you know the total has not changed?
  • Which partition would help you calculate mentally?
  • Can you record your partition using numbers?

Common Misconceptions

Believing the whole changes when the parts are rearranged

Recombine the two parts and recount the total. Emphasise that the arrangement changes, but the quantity stays the same.

Confusing a part with the whole

Use clearly labelled part-part-whole mats and ask students to point to each part before identifying the total.

Seeing only one way to partition a number

Systematically move one counter at a time from one part to the other and record every new combination.

Thinking 35 must always be 3 tens and 5 ones

Exchange one tens rod for 10 ones to show that 35 can also be represented as 2 tens and 15 ones.

Counting the parts without checking the total

Ask students to recombine the parts and verify that they still match the original whole.

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Year 1 Number Partitioning Activities

Activity 1: Split the Collection

Give students a collection of counters and two hoops or trays. Students split the collection into two parts and identify the whole.

Repeat the task to find as many different partitions as possible.

Curriculum connection: AC9M1N02

Activity 2: Make 10 on a Ten-Frame

Place a number of counters on a ten-frame. Students identify how many more are needed to fill the frame.

Record the matching number bond, such as 6 and 4 make 10.

Curriculum connection: AC9M1N02_E1

Activity 3: Number Bond Partners

Give each student a number card from 0 to 10. Students move around the room to find the partner whose number combines with theirs to make 10.

Pairs explain and record their number bond.

Curriculum connection: AC9M1N02_E1

Activity 4: Shake and Spill

Place 10 two-colour counters in a cup. Students shake and spill them, then record the two colour groups as parts of the whole.

Repeat and compare the different combinations.

Curriculum connection: AC9M1N02_E1

Activity 5: Build Tens and Ones

Give students a two-digit numeral card. They build the number using base-ten blocks and place the materials on a tens-and-ones mat.

Students say and record the partition.

Curriculum connection: AC9M1N02_E2

Activity 6: Trade a Ten

Build a number such as 35 using 3 tens and 5 ones. Exchange one tens rod for 10 ones.

Students compare 3 tens and 5 ones with 2 tens and 15 ones and explain why both represent 35.

Curriculum connection: AC9M1N02_E2

Activity 7: Partition 24 in Different Ways

Build 24 using materials. Students record partitions such as 20 and 4, 10 and 14, or 10, 10 and 4.

Display the different representations and discuss what remains unchanged.

Curriculum connection: AC9M1N02_E3

Activity 8: Part-Part-Whole Mat Challenge

Place a whole number in the top section of a part-part-whole mat. Students choose two or more parts that combine to make the whole.

Ask students to find a different partition each time.

Curriculum connection: AC9M1N02_E3

Activity 9: Mystery Partition

Give clues such as, “My whole is 18. One part is 10. What is the other part?” or “I have 2 tens and 7 ones. What is my number?”

Students solve the mystery using materials or drawings.

Curriculum connection: AC9M1N02

Activity 10: Choose a Helpful Partition

Present a simple calculation such as 8 + 6. Students partition 6 into 2 and 4 so that 8 and 2 make 10.

Discuss how flexible partitioning can make mental calculation easier.

Curriculum connection: AC9M1N02

Differentiation

Support

  • begin with numbers to 5 before extending to 10;
  • use real objects that students can physically move;
  • use five-frames and ten-frames;
  • provide completed examples on part-part-whole mats;
  • use one partition at a time before comparing several;
  • keep two-digit work to whole tens and small ones;
  • use colour coding for tens and ones;
  • allow oral explanations and adult scribing;
  • recombine the parts after every partition.

Extension

  • partition numbers beyond 50;
  • use three or more parts;
  • record all possible two-part partitions of a number;
  • rename two tens as 20 ones;
  • compare efficient and inefficient partitions;
  • use partitioning to solve mental addition and subtraction;
  • create mystery partition clues for classmates;
  • explain two different representations using place value language;
  • record partitions using equations.

Mathematical Sentence Starters

The whole is _____.

The two parts are _____ and _____.

_____ and _____ combine to make _____.

I know these parts make the whole because _____.

There are _____ tens and _____ ones.

I renamed one ten as _____ ones.

_____ can also be partitioned as _____ and _____.

The total stayed the same because _____.

This partition is helpful because _____.

I found another way by _____.

Assessment Ideas

Observe whether the student can:

  • identify the whole and the parts;
  • partition a number to 10 in more than one way;
  • find number pairs that combine to make 10;
  • use a ten-frame to identify a missing part;
  • represent a two-digit number using tens and ones;
  • rename one ten as 10 ones;
  • partition the same two-digit number in different ways;
  • record partitions using numerals;
  • explain why the total remains unchanged;
  • choose a useful partition for mental calculation.

Quick Exit Ticket

  1. Show 10 counters.
  2. Split them into two parts.
  3. Record the two parts.
  4. Build 24 and show two different partitions.

Printable Teacher and Student Resources

Use the buttons below to open the available AC9M1N02 teaching materials and printable activities in a new browser tab.

Main Worksheets Partitioning Numbers and Place Value Part-Part-Whole Worksheets Making 10 Activities Tens and Ones Worksheets Partitioning Numbers Worksheets Part-Whole Number Partition Activities Flexible Number Partitioning

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Home Learning Ideas

Families can practise number partitioning using toys, socks, fruit, pegs, buttons, coins or building blocks.

Choose a whole number, split the collection into two groups and ask the child to find another way to make the same total.

Ask questions such as:

  • What is the whole?
  • What are the two parts?
  • Can you split it another way?
  • Which two numbers make 10?
  • How many tens and ones are in this number?
  • Can you rename one ten as 10 ones?
  • How do you know the total stayed the same?
  • Which partition would help you calculate quickly?

Related Year 1 Maths Chapters

Chapter 1: Numbers to 120 – AC9M1N01 Addition and Subtraction Activities Place Value Activities Number Bonds Activities