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.
Step 1: Lesson Standards & Learning Goals
The focus of this standard is placed on the conceptual understanding of determining whether numbers within 20 are even and odd numbers and proving the evenness or oddness of numbers with objects, drawings, and equations with 2 equal addends.
When pairing objects, students should represent even numbers with equations to represent the pairs. For example, if given 6 objects, a students may write 2 + 2 + 2 = 6 or 3 + 3 = 6 to represent their picture. While both equations are mathematically correct, the expectation for second graders is to apply the concept of doubles to the concept of odd and even numbers. Students should understand that if a number can be decomposed (broken apart) into two equal addends or doubles addition facts (e.g., 10 = 5 +5), then that number is an even number. Students should explore this concept with concrete objects (e.g., counters, cubes, etc.) before moving towards pictorial representations such as circles or arrays.
*While noticing that even numbers end in 0, 2, 4, 6, and 8 is an interesting and useful observation, it should not be used as the definition of an even number.
How can you determine whether a number is even or odd?
What patterns do we observe when counting odd and even numbers?
What strategies can we use to add and subtract odd and even numbers efficiently?
addends
decompose
doubles
equal sign (=)
equation
even number
odd number
pair
sum
odd number
Determine whether a group of objects (up to 20) has an odd or even number of members by pairing objects or counting them by 2’s.
Understand the terms even (numbers that can be divided into groups of 2 with no leftovers) and odd (numbers that can be divided into groups of 2 with 1 left over).
Explore the relationship between even numbers and double addends.
Write an equation to express an even number as a sum of two equal addends.
Extend understanding of even and odd numbers to numbers greater than 20.
Some numbers can be divided into two equal parts (even numbers) and some cannot (odd numbers).
Repeated addition of the same addend involves joining equal groups.
Step 2: Assessment
NC.2.OA.3 - CO - Howell - Nov. 18, 2022
NCDPI Assessments
Grade 2 Math Assessment Practice Prompts
Step 3: Lesson Instructions
Read Aloud
Exploration or Experience
Give students a set of counting bears or objects to pair. (If all bears have a friend, the number is even. If there is one left over, the number is odd. )
Video Clip
Tools 4 NC Teachers
Math Expressions - (Barnes and Hearne) - Standards Alignment
Motivation Math
Think Up! Math
Khan Academy - 2nd Grade Math
Eureka Math/Engage NY Free Resources
Embarc Online (Eureka Math) -
G2 M6 Topic D: The Meaning of Even and Odd Numbers
Zearn Math - Online Support Practice for Eureka Math (Requires free account)
North Carolina Collaborative for Mathematics Learning - Grade 2 Instructional Framework
NCDPI Resources
Grade 2 Math Assessment Practice Prompts
Grade 2 Released Summative Assessments
Thinking Blocks - Word Problem Practice with Bar Diagrams
