PS 42X Grade 1 Unpacking

Grade 1: Unit 3 – Addition Strategies

PD Activity:

  • Understanding Problem Types (See: CCSS, pg. 88 or NC Unpacked, pg. 32)
  • Levels for calculating sums (See pg. 127E in TE, NC Unpacked, pg. 12 – 13)
  • We add like units. 2 birds + 3 fish
  • Fluency Carousel (adapted): What is the doubles fact that I would use to figure out this problem (See pg. 159 “Math Talk in Action”)

Recommended comprehension strategies for problem solving:

  • A line at a time
  • Visualizing
  • Making a mathematical sketch (look at pg. 2 – 3)
  • What is the question? (Problem Posing)
  • Rework a problem (by changing the numbers)
  • What do the numbers mean?
  • Match the Mathematical Sketch and Model

Online Resources:


Stage 3: Flexible, Effective Strategies

  • Use tools to explain and solve word problems
  • Using tools, models and strategies for sums up to 20
  • Explaining how and when to use a strategy
  • Decomposing number
  • Using precise math language to describe tools, models, strategies and parts of an equation

Stage 4: Automaticity (with conceptual understanding)

  • Compliments of 5 and 10
  • Plus 1/Minus 1 Facts
  • Single-digit doubles facts


  1. Lesson 2.1: Use a “Match Mine” Kagan Strategy consistently throughout unit to get students using precise math vocabulary and reasoning about quantities. (Lesson 3.1). Have students build on a ten-frame. Adaptation: “Find Your Match” – students are given an equation and they have to find the other person in the classroom that has the same sum. For example, 8 + 9 = 17 finds 9 + 8 = 17. Use this for develop an understanding of the Commutative Property of Addition via a discussion as to why that person is your match.
  2. Use “Quiz,Quiz Trade” Kagan Strategy consistently throughout unit to get students to develop reasoning with addition facts (Lesson 3.1).
  3. Lesson 3.1: Use concrete models on the ten-frame. Write calculations as equations. Give a context to equations. Turn the work book page #132 into an activity. For example, have two cards in a baggie and have students find the sum, then rewrite the equation by reversing the order of the addends. Let the students discover that Commutative Property of Addition…do not tell then the name of that Property of Operation until after they notice that the order does matter when adding. You might mention and model on a number line that order does matter for subtraction.
  4. In all lessons be mindful of different problem types and the challenges that they might present conceptually to students.
  5. Lesson 3.2 introduces a counting on strategy. Pre-assess students to find out who already uses this strategy and use those students to partner with students who have not adopted that strategy. Model a static number and counting on with cubes, on a number line, a number grid, and with fingers.  The book emphasizes starting with the larger number, but it does not matter.
  6. For Lessons 3.1 and 3.2 would revise the numbers to all be compliments of 10 as the “Make a 10” strategy is one of the benchmark strategies for students to be able to use consistently. Need to spend at least 2-days with is strategy. Look at pg. 137B…use this strategy to teaching counting on.
  7. Lesson 3.3: Model concretely. Pre-assess students to know knows their doubles facts at a Stage 4: Automaticity. Make the connection to using doubles to figure out 1 more or 1 less (Lesson 3.5).  Student need to be able to see the nested numbers in order to use their knowledge of doubles facts to find sums. For example, a student has to be able to see that 3 + 4 is also 3 + (3 + 1) and then do (3 + 3) + 1.
  8. Lesson 3.4: use Number Bonds to model in conjunction with concrete objects. Turn Lesson 3.4 Enrich into a Math Center. For #5 on page 151, this is an opportunity to problem solve by acting out and using authentic materials. The “Problem Solving Application” needs to be build concretely. Adapt the idea in the book, but do not use the activity as indicated in the book.
  9. Use the Addition Chart in Guided Math groups, but do not assume that students understand what it means otherwise.
  10. Lesson 3.6 should be made into centers where students can pick which strategy they will use and why. See pg. 163 “Do On You Own”…you want students to make a decision about which strategy to use and be able to explain why.
  11. Lesson 3.7 can be introduced as a guided group, while centers are going on for lesson 3.6. The important skills here is recognizing and using the pattern and structure (Mathematical Practices #7 and 8). Model concretely. Subitizing flash cards would be of use here for students to see amounts quickly. Adapted #18 on pg. 170 into a math center game by having images on 1 card and equations on another. Good activity for “Find My Match”.
  12. Lesson 3.8: it is vital that students have the opportunity to act out the equations. Have students make up stories about the equations to provide a context. Have students work in partnership to model how 9 + 5 can be seen as 10 + 4. Enrich activity can be used in a center. Good activity for “Find My Match”. Should combine Lesson 3.8 and 3.9. Use the “Advanced Learners” on pg. 180 as a math center.
  13. Lessons 3.10 and 3.11 (combine): Use the “Addition Tic Tac Toe” on page 185B. Use ten-frames. Focus should be on looking for opportunities to use doubles facts or make a 10 strategies. “Advanced Learners” activity on pg. 186 is a great center. Have students prove ideas and reasoning. Can have focus on making 10, e.g. 8 + ___ + 2 = 12. Would write horizontally. Could use number line or number strip to structure thinking. With that idea, you can bring in the Associative Property of Addition. For example, “8 + ___ + 2 = 12” can be rewritten as “8 + 2 + ___ = 12”. Write calculations as equations.
  14. Lesson 3.12: Infuse problems starting in the middle of the unit. Act out, make sketches and model. Have students work in triads, but tell specific students to use specific strategies.
  15. Tools: ten-frames, counters, physical number line, dominos, number path
  16. Models: tape/bar diagram, number line, number bond
  17. Strategies: counting all, counting-on, recognizing nested doubles facts and then using that knowledge to solve problems,


  • Story Mats: (pg. 127I)
  • Sum Concentration: Index cards with sums and other index cards with expressions. (adapted from pg. 130)
  • Ten-Frames for visualizing doubles facts with dominos (See “Advanced Learner, pg. 144)
  • Sheet Protected Number Grid/Number Paths or Number Lines to Count On (See “Advanced Learner, pg. 138)
  • Doubles, Plus 1 Quick Fold: important that students write the equations and indicate the doubles fact.
  • Number Cube Fluency (adapted from pg. 149B “Fluency Builder”): students role the dice and determine the sums. They should have a list of sums and cross out the sums as they get them. The person/partnership that crosses out all the sums first wins.
  • Make “Addition Tic Tac Toe” Boards (adapted from Lesson 3.10)

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