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Grade 1 · unit review

Review: Use Efficient Strategies Within Twenty

Use ten, doubles, friendly groupings, and related addition to calculate.

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Unit review questions
1. Use a ten to find 8 + 7.
Need a hint?
  • Only use enough of the second addend to reach ten.
  • After filling ten, add the leftover part, not the full addend again.
2. Use a near double to find 7+8.
Need a hint?
  • Confirm the addends differ by one.
  • A near double includes one more than the exact double.
3. Group a ten to find 6+4+7.
Need a hint?
  • Circle the two parts that make ten.
  • Changing the grouping must not lose or repeat an addend.
4. Subtract through ten: 16−9.
Need a hint?
  • Keep track of how much has already been removed.
  • Do not remove the entire subtrahend again after reaching ten.

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Use the skills in a new task

Calculate 8+7 using ten and 6+7 using a double. Show the split or adjustment in each method.

Work on paper or in your own document. Explain the choices you made.

  • Draw or label the numbers or shape features the task gives you.
  • Say why each calculation or shape choice follows the ideas in this unit.
  • Check that your answer fits the story or drawing in the task.
Compare with a model response

8+7=8+2+5=15. For 6+7, double six is twelve; add one more to get thirteen. Each strategy keeps the original total.

A different response can also meet the criteria. Compare the evidence and reasoning, rather than copying the wording.