Addition with Animal Weights

Title: Everyday Math (Animal Weights)

Date: Wednesday, November 8, 2007

Rationale: Students will gather practice with addition of two-digit numbers.

Objectives: 1) Students will demonstrate their ability to model their math activities in their journals. 2) Students will complete two-digit addition, using base-ten models.

Patterns, Functions and Algebra goals (From Everyday Mathematics curriculum)

Benchmarks per ICCSD:

Algebra - Know how to explore algebraic concepts and processes.
Whole Numbers: Concepts of Operations and Computation - Use addition, subtraction, multiplication and division of whole numbers.


  • Whiteboards + Markers
  • Chart paper + markers
  • Animal Cards (from activity sheet 7/8)
  • Two Kinds of dice
  • Math masters 353 (shaker) copies; 139
  • Counters (for Shaker Top-It)
  • Math Journal Pg. 88, 86
  • Paper Plates + base-10 blocks

Procedure (approx. 55 min):

Launch: Mental Math, Message, and introduction (15 min)

  • Dominoes, and ask students to write a number fact for the numbers on the dominoes (Part + part= total)
  • Message: Fox = 14 lbs. Cat = 7 lbs. If they were to both be sitting on a scale, what would be their total weight?
    • How do you know that? What strategies did you use? What materials could you use to figure that problem out? (Math materials?)
    • Record students suggestions on Chart paper
  • Model how to find weight using base-10 blocks as a strategy. Have students bring their notebooks to group, to work together. J
    • Introduce the abbrev. Lbs. for pounds.
    • Use Animal Cards; show how both sides look the same, but are showing two different things. These numbers represent what you could expect from that animal, but often differ, just as people weigh lots of different things.
    • Show, on the board, how to do so for the raccoon and fox.
    • Show, how to do the Cat (7) and Koala (19)…Ask students to explain how they got the answers.
    • Repeat routine, having student volunteers come to the board (while remaining students use their) Boy/Girl; Raccoon/Eagle; Cat/eagle; koala/fox.

Additional Explore:

  • Shaker Addition Top-It
  • Solving Parts-and-Totals Problems (Independent)
  • p. 139 MM, plates, base-10 blocks
  • Start-Change-End
  • Second graders challenge
  • Math Boxes pg. 86 then 88

Summarize: Share strategies using base-10 blocks, other materials, or written records.


4 partners using polyhedral dice.
Shaker Addition Top-It.

-3 animals
- # stories/sentences
-Record in notebook (MODEL how to do)
- Draw what they did w/unit-10 blocks


Animal Weight Top-It
- Need both partners’ sets of cards.

Readiness: Independent

Part, Part, Total paper plates using base-10 blocks (using Math Masters pg. 139)
-Divide paper plate into three sections. Total is on the top, with the two parts on the bottom.


  • Collect students’ journals to review their recording. Circulate the room. Can students explain their addition to you, verbally? Show you with their models?

Lesson Success

_______Excellent _________Good _______Fair ______Flop

Lesson template adapted from Amy Schneider

For questions or comments, please contact Mari Hauf