Year 2 Mathematics · AC9M2A02

Recall and demonstrate proficiency with addition facts to 20; extend and apply facts to develop related subtraction facts

Build fluent addition facts to 20 with doubles, near doubles, making 10 and systematic partitioning, then use each addition fact to derive related subtraction facts

Ready to project and teach

Learning goalsSay it simply

Students move from counting to recalling and deriving addition facts efficiently. They use ten-frames, counters and part-part-whole diagrams to explain why a strategy works before practising until the facts can be recalled.

  • Recall doubles and combinations that make 10.
  • Derive near doubles by adjusting a known double by one.
  • Bridge through 10 by partitioning one addend.
  • Rearrange parts without changing the total.
  • Use one addition fact to state two related subtraction facts.
  • Record partitions systematically and explain how the list is complete.
Clean visual examplesOne-page board

Clean one-page examples

AC9M2A02 - Recall and demonstrate proficiency with addition facts to 20; extend and apply facts to develop related subtraction facts
Example 1

Content description: recall and demonstrate proficiency with addition facts to 20; extend and apply facts to develop related subtraction facts

Example 2

: using ten-frames or materials such as connecting cubes to develop and record addition and subtraction strategies including doubles, near doubles, counting on, combinations to 10 and bridging to 10, explaining patterns and connections noticed within the facts

Example 3

: partitioning and rearranging collections to practice and develop fluency with addition and subtraction facts to 20 leading to the recall of these facts; for example, partitioning using materials and part-part-whole diagrams to develop subtraction facts related to addition facts, such as 8 + 7 = 15 therefore, 15\space - \space7 = 8 and 15 \space- \space8 = 7

Example 4

: using partitioning to develop and record facts systematically; for example, “How many ways can 10 birds be spread among 2 trees?”, 10 = 10 + 0, 10 = 9 + 1, 10 = 8 + 2, 10 = 7 + 3, …; explaining how they know they have found all possible partitions

Curriculum examplesCurriculum examples

The content description and elaborations below show the curriculum ideas taught in this unit. Items marked as teaching context support lesson planning.

  • Content description: recall and demonstrate proficiency with addition facts to 20; extend and apply facts to develop related subtraction facts
  • E1: using ten-frames or materials such as connecting cubes to develop and record addition and subtraction strategies including doubles, near doubles, counting on, combinations to 10 and bridging to 10, explaining patterns and connections noticed within the facts
  • E2: partitioning and rearranging collections to practice and develop fluency with addition and subtraction facts to 20 leading to the recall of these facts; for example, partitioning using materials and part-part-whole diagrams to develop subtraction facts related to addition facts, such as 8 + 7 = 15 therefore, 15\space - \space7 = 8 and 15 \space- \space8 = 7
  • E3: using partitioning to develop and record facts systematically; for example, “How many ways can 10 birds be spread among 2 trees?”, 10 = 10 + 0, 10 = 9 + 1, 10 = 8 + 2, 10 = 7 + 3, …; explaining how they know they have found all possible partitions
Questions and answersWith answers

Key idea: Addition facts to 20 support fast calculation. Related subtraction facts use the same whole and parts.

Remember

  • Recall addition facts
  • Use doubles
  • Use make ten
  • Write related subtraction
  • Apply facts

Quick questions

  • Write a fact family for 7, 8 and 15.
  • Use make ten to solve 9 + 5.
  • What addition fact helps with 16 − 7?
  • Why is 15 − 8 not the same as 8 − 15?

If an answer is uncertain, return to the model and explain what each part represents before calculating or drawing a conclusion.

Practice and reviewReady for practice
  • Counting every item: prompt with “Which double or make-10 fact can help?”
  • Losing part of an addend: after splitting 7 into 2 and 5, check that 2 + 5 still equals 7.
  • Subtracting in the wrong direction: identify the whole first; subtraction starts with the whole.
  • Writing unrelated equations: keep the same two parts and whole in all four equations.
  • Repeating or missing partitions: change each part by one in opposite directions and mark the endpoints.

Read the topic guide and use the teacher slide for instruction. Students can then use the worksheet for written work, open Practice for supported feedback, or take the Test when they are ready.

Curriculum alignmentStart here

Students move from counting to recalling and deriving addition facts efficiently. They use ten-frames, counters and part-part-whole diagrams to explain why a strategy works before practising until the facts can be recalled.

  • Recall doubles and combinations that make 10.
  • Derive near doubles by adjusting a known double by one.
  • Bridge through 10 by partitioning one addend.
  • Rearrange parts without changing the total.
  • Use one addition fact to state two related subtraction facts.
  • Record partitions systematically and explain how the list is complete.
Related resourcesKeep teaching

Related Classroom Views

Continue through closely related Year 2 Maths concepts.

Explore all Year 2 Maths topics

Teach & ExplainTeaching slides and samples

Teach this topic step by step

Explore optional teaching slide packs for classroom lessons and explanations at home.

Browse Teach & Explain · Browse Print & Go

Teachers: follow SkillrHub on TPT, then email us to request a free sample before buying. Include the year, subject and topic or curriculum code.

Request a free sample

After trying the sample, honest feedback is welcome. A TPT review is optional, where available, and does not need to be positive.