Domain

Operations and Algebraic Thinking

Cluster

Work with equal groups

Standard(s)

NC.2.OA.3 Determine whether a group of objects, within 20, has an odd or even number of members by:

●       Pairing objects, then counting them by 2s.

●       Determining whether objects can be placed into two equal groups.

●       Writing an equation to express an even number as a sum of two equal addends

Materials

student form, pencil, paper, bags of 20 counters (teddy bears, Unifix cubes, etc.)

Task

This task can be administered whole group or small group. Provide materials to the students.

Task 1:  Direct students to create an even group of objects using the counters. Students will draw a picture of their model and explain how they know the grouping is even.  Students will also write an equal addend equation showing the even number of counters.   

Task 2:  Direct students to create an odd group of objects using the counters. Students will draw a picture of their model and explain how they know the grouping is odd.  Students will also write an equation showing the odd number of counters.  

Continuum of Understanding

Not Yet Proficient

Needs prerequisite concepts:

Checklist for teacher to identify mastery of standard:

❑    Pairs group members or puts them into two equal groups

❑    Clear justification

❑    Writes an equation with two addends that represents that group (addends can be equal if there are an even number of group members)

Progressing

Student does one or two of the following:

●   Correctly identifies group as odd or even

●   Explanation justifies even/odd concept

●   Equation represents grouping (addends are equal if there are an even number of group members)

Meets Expectation

●   Correctly identifies groups as even or odd by pairing counters or dividing them into two equal groups.

●   Clear justification

●   Writes an equation to correctly express group members with two addends, using equal addends to prove the even group.