Practice Problems — Set 18

2.OA.B.2 · Fluently add and subtract within 20 using mental strategies

Print and write your answers. Use diagrams to show thinking.

Warm-up

1. Talk through today's focus: Fluently add and subtract within 20 using mental strategies 2. Try one oral example together before writing. 3. Use the diagram to explain your thinking.

_See printable PDF for diagram._

Written practice

1. 6 + 5 = ___ 2. 11 − 6 = ___ 3. 5 − 2 = ___ 4. 2 + 1 = ___ 5. Fill in: 4 + ___ = 5 6. Without counting from 1, solve: 3 + 1 = ___ 7. Explain your thinking for set 18 in one sentence. 8. Create your own problem for 2.OA.B.2.

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More written practice

1. Apply Fluently add and subtract within 20 using mental strategies (item 9, set 18): show your work. ___ 2. Apply Fluently add and subtract within 20 using mental strategies (item 10, set 18): show your work. ___ 3. Apply Fluently add and subtract within 20 using mental strategies (item 11, set 18): show your work. ___ 4. Apply Fluently add and subtract within 20 using mental strategies (item 12, set 18): show your work. ___ 5. Apply Fluently add and subtract within 20 using mental strategies (item 13, set 18): show your work. ___ 6. Apply Fluently add and subtract within 20 using mental strategies (item 14, set 18): show your work. ___

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Patterns and rules

1. Identify the rule in today's 2.OA.B.2 practice. 2. Show your work with a drawing or diagram. 3. Explain your answer to a parent.

_See printable PDF for diagram._

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Stretch

1. Create your own 2.OA.B.2 question for a parent to solve. 2. Explain your method in two sentences.

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Parent tip: Short daily practice — 5 minutes