Topic Two: Work with Equal Groups

Pacing (Duration of Unit):

Desired Results


Standards for Mathematical Practices
1. Make sense of problems and persevere in solving them.
2. Reason abstractly quantitatively.
3. Construct viable arguments and critique the reasoning of others.
4. Model with mathematics.
5. Use appropriate tools strategically.
6. Attend to precision.
7. Look for and make use of structure.
8. Look for and express regularity in repeated reasoning.
Established Goals:

2.OA.A.1-Use addition and subtraction within 100 to solve one- and two-step word problems involving situations of adding to, taking from, putting together, taking apart, and comparing, with unknowns in all positions, e.g., by sung drawings and equations with a symbol for the unknown number to represent the problem.

2.OA.B.2-Fluently add and subtract within 20 using mental strategies. By end of Grade 2, know from memory all sums of two one-digit numbers.

2.OA.C.3-Determine whether a group of objects (up to 20) has an odd or even number of members, e.g., by pairing objects or counting them by 2s; write an equation to express an even number as a sum of two equal addends.

2.OA.C.4-Use addition to find the total number of objects arranged in rectangular arrays with up to 5 rows and up to 5 columns; write an equation to express the total as a sume of equal addends.

Student I Can Statements:
  • I can use strategies to solve addition word problems. (within 100)
  • I can use strategies to solve subtraction word problems. (within 100)

Prerequisite Standards:





Big Ideas:
Equivalence-Any number, measure, numerical expression, algebraic expression, or equation can be represented in an infinite number of ways that have the same value.

Operation Meanings and Relationships-There are multiple interpretations of addition, subtraction, multiplication and division of rational numbers, and each operation is related to other operations.

Basic Facts and Algorithms-There is more than one algorithm for each of the operations with rational numbers. Some strategies for basic facts and most algorithms for operations with rational numbers, both mental math and paper and pencil, use equivalence to transform calculations into simpler ones.

Practices, Processes, and Proficiencies-Mathematics content and processes can be applied to solve problems.
Essential Questions:
  • How can you show even and odd numbers?
  • How do arrays relate to repeated addition?
Students will know...
  • Numbers can be classified as even or odd by showing numbers as two equal parts.
  • A group of objects (or number) can also be classified as even or odd by analyzing skip-counting patterns. An even number can be written as a sum of equal addends.
  • An array shows equal groups, so you can write equations using repeated addition to find the total number of objects in an array.
  • You can make arrays and write equations using repeated addition to help solve problems.
  • Good math thinkers use math they know to show and solve problems.

  • even
  • odd
  • array
  • rows
  • columns
  • bar diagram
Students will be skilled at...
  • Explain if a group of objects is even or odd.
  • Explain different ways to tell if a group of objects shows an even or odd number.
  • Find the total number of objects in a set of rows and columns.
  • Create arrays with equal rows or equal columns to solve addition problems.
  • Model problems using equations, drawings, arrays, and bar diagrams.

Assessment Evidence

Performance Assessment:

Other Evidence:

Learning Plan

Learning Activities:

2-1 Even and Odd Numbers

2-2 Continue Even and Odd Numbers

2-3 Use Arrays to Find Totals

2-4 Make Arrays to Find Totals

2-5 Math Practice and Problem Solving: Model with Math


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