Partitioning tens and ones: Year 1 Maths topic guide

What students learn in AC9M1N02

This unit helps students build a clear, usable understanding of Partitioning tens and ones. The goal is not to memorise one answer pattern. Students should be able to explain the idea, recognise it in a new example and apply it in a short practice or worksheet task.

• Start with the main idea: partition one- and two-digit numbers in different ways using physical and virtual materials, including partitioning two-digit numbers into tens and ones.
• Use concrete examples, pictures, oral explanation and short written responses before moving to independent practice.
• building knowledge and understanding of the part-part-whole facts to 10, using physical and virtual materials; for example, using virtual ten-frames through a digital app or website to identify pairs of numbers that combine to make 10 using 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
• Finish with mixed questions so students must choose the correct strategy rather than copy the last example.

Curriculum coverage and elaborations

The content description and elaborations below show the curriculum ideas taught in this unit. Items marked as teaching context support lesson planning but may not appear in the initial eight-question activity.

• Content description: partition one- and two-digit numbers in different ways using physical and virtual materials, including partitioning two-digit numbers into tens and ones
• E1: building knowledge and understanding of the part-part-whole facts to 10, using physical and virtual materials; for example, using virtual ten-frames through a digital app or website to identify pairs of numbers that combine to make 10
• E2: using 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
• E3: using part-part-whole reasoning and physical or virtual materials to represent 24, then partitioning 24 in different ways and recording the partitions using numbers; for example, 10, 10 and 4 combine to make 24 or 10 and 14 combine to make 24

How to use this unit

Read the topic guide, use the teacher slide for instruction, then complete the Worksheet, Practice and Test. These three activities use the same eight-question unit bank.

Common mistakes to watch for

• Rushing to a rule before checking the concrete model, drawing or number sentence.
• Using the correct answer once but not being able to explain why it works.
• Mixing up similar vocabulary such as more/less, before/after, longer/shorter or equal groups/sharing.

International curriculum mapping

This table gives closest-topic mapping for search and planning. The Australian Curriculum code is exact; overseas entries are broad equivalents because each jurisdiction structures outcomes differently.

Related Year 1 Maths topics

• AC9M1N01: Numbers to 120
• AC9M1N03: Skip counting and equal groups
• AC9M1N04: Addition and subtraction within 20
• AC9M1N05: Additive problem solving and money
• AC9M1N06: Equal sharing and grouping
• AC9M1A01: Skip-counting pattern sequences
• AC9M1A02: Repeating patterns
• AC9M1M01: Comparing length, mass, capacity and duration

Official curriculum references

• Australian Curriculum Version 9.0
• Victorian Curriculum F-10
• NSW Curriculum
• Common Core State Standards
• Next Generation Science Standards
• England National Curriculum
• New Zealand Curriculum
• NCERT textbooks