Study Guide — 1.OA.A.1
Use addition and subtraction within 20 to solve word problems involvi…
Solve one- and two-step word problems by modeling and choosing operations.
What this standard means
- Use addition and subtraction within 20 to solve word problems involving situations of adding to, taking from, putting together, taking apart, and comparing, with unknowns in all positions, e.g., by using objects, drawings, and equations with a symbol for the unknown number to represent the problem.1
- Apply use addition and subtraction within 20 to solve word problems involvi… with models and explanation
- Models the problem with a drawing
_See printable PDF for diagram._
How to use the 20 practice sets
| Sets | When to use | | --- | --- | | 1–5 | Intro — explore together, short written items | | 6–10 | Core skills — diagrams and written practice | | 11–15 | Mixed review — explain thinking | | 16–20 | Stretch — word problems and mastery tasks |
Pacing: 10–15 minutes per session.
How to practice
1. Underline the question and key numbers 2. Draw a bar model or diagram 3. Check whether the answer fits the story
_See printable PDF for diagram._
Common mistakes
- Using the wrong operation
- Stopping after one step in two-step problems
Review and practice tests
1. Start Review 1/10 when sets 1–3 feel comfortable. 2. Move up one review level with little help. 3. Use Practice Test 4/10–6/10 for mid-standard checks. 4. Practice Test 10/10 is the mastery bar for 1.OA.A.1.
- [ ] Models the problem with a drawing
- [ ] Chooses correct operation(s)
- [ ] Answers in complete sentences with units
Materials for this standard
- Practice Problems — 20 printable sets
- Review — 10 difficulty levels
- Practice Test — 10 difficulty levels
- Answer key — for parents and tutors