Mental strategies from known facts
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Use the known fact 7 + 8 = 15. What is 37 + 8?
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Answer: 45
- 37 is 30 and 7.
- Use the small fact on the ones: 7 + 8 = 15.
- Keep the tens: 30 + 15 = 45.
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Curriculum reference
Victorian Curriculum F–10 Version 2.0
Pi Leo practice scope
Use doubles, friendly tens and compensation without a calculator.
Read the official VCAA curriculum description (VC2M3A02)
These quizzes practise concepts within this topic. Multiple-choice answers alone do not demonstrate drawing, conducting an investigation or using a digital tool.
Activities to practise beyond the quiz
- Supported by the guided activity; selecting an MCQ does not demonstrate this action.
- VC2M3A02-C01Parts, totals and differences.
- VC2M3A02-C02Find an unknown part or choose a model.
- VC2M3A02-C03Work backwards and check the whole.
- VC2M3A02-C04Demonstrate and explain selected mental strategies without a calculator
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Subskills
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Descriptor-derived subskills
- D01Parts, totals and differencesParts, totals and differences.
- D02Find an unknown part or choose a modelFind an unknown part or choose a model.
- D03Work backwards and check the wholeWork backwards and check the whole.