Answer Key — 1.OA.C.6

For parents and tutors

Do not share with students before practice tests.

Practice Problems — Sets 1–10

| Set | Guidance | | --- | --- | | Set 1 | Add and subtract within 20, demonstrating fluency for addition and su… — verify written work and accept reasonable drawings. | | Set 2 | Add and subtract within 20, demonstrating fluency for addition and su… — verify written work and accept reasonable drawings. | | Set 3 | Add and subtract within 20, demonstrating fluency for addition and su… — verify written work and accept reasonable drawings. | | Set 4 | Add and subtract within 20, demonstrating fluency for addition and su… — verify written work and accept reasonable drawings. | | Set 5 | Add and subtract within 20, demonstrating fluency for addition and su… — verify written work and accept reasonable drawings. | | Set 6 | Add and subtract within 20, demonstrating fluency for addition and su… — verify written work and accept reasonable drawings. | | Set 7 | Add and subtract within 20, demonstrating fluency for addition and su… — verify written work and accept reasonable drawings. | | Set 8 | Add and subtract within 20, demonstrating fluency for addition and su… — verify written work and accept reasonable drawings. | | Set 9 | Add and subtract within 20, demonstrating fluency for addition and su… — verify written work and accept reasonable drawings. | | Set 10 | Add and subtract within 20, demonstrating fluency for addition and su… — verify written work and accept reasonable drawings. |

Practice Problems — Sets 11–20

| Set | Guidance | | --- | --- | | Set 11 | Add and subtract within 20, demonstrating fluency for addition and su… — verify written work and accept reasonable drawings. | | Set 12 | Add and subtract within 20, demonstrating fluency for addition and su… — verify written work and accept reasonable drawings. | | Set 13 | Add and subtract within 20, demonstrating fluency for addition and su… — verify written work and accept reasonable drawings. | | Set 14 | Add and subtract within 20, demonstrating fluency for addition and su… — verify written work and accept reasonable drawings. | | Set 15 | Add and subtract within 20, demonstrating fluency for addition and su… — verify written work and accept reasonable drawings. | | Set 16 | Add and subtract within 20, demonstrating fluency for addition and su… — verify written work and accept reasonable drawings. | | Set 17 | Add and subtract within 20, demonstrating fluency for addition and su… — verify written work and accept reasonable drawings. | | Set 18 | Add and subtract within 20, demonstrating fluency for addition and su… — verify written work and accept reasonable drawings. | | Set 19 | Add and subtract within 20, demonstrating fluency for addition and su… — verify written work and accept reasonable drawings. | | Set 20 | Add and subtract within 20, demonstrating fluency for addition and su… — verify written work and accept reasonable drawings. |

Review tiers 1–10

• Checklists are parent-judged.
• Written items: verify against practice set patterns.
• Standard text: Add and subtract within 20, demonstrating fluency for addition and subtraction within 10. Use strategies such as counting on; making ten (e.g., 8 + 6 = 8 + 2 + 4 = 10 + 4 = 14); decomposing a number leading to a ten (e.g., 13 - 4 = 13 - 3 - 1 = 10 - 1 = 9); using the relationship between addition and subtraction (e.g., knowing that 8 + 4 = 12, one knows 12 - 8 = 4); and creating equivalent but easier or known sums (e.g., adding 6 + 7 by creating the known equivalent 6 + 6 + 1 = 12 + 1 = 13).

Practice test scoring

| Tier | Pass guidance | | --- | --- | | 1–3 | Most oral tasks smooth; majority of written correct | | 4–6 | 7/10+ total with clear understanding | | 7–8 | 9/12+ with explanations | | 9–10 | Near-perfect; ready to move on |

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