Students discover the difference between odd and even numbers through the exploration of decomposing numbers into equal groups or pairs. This unit extends prior knowledge by incorporating doubling strategies for addition and subtraction fluency to 20 and the decomposition of whole numbers, developing the foundation for multiplication and division in Grade 3. Students are likely to struggle with the understanding that an even number is either the sum of 2 equal whole addends or the result of taking the even number and breaking it up into pairs with no leftovers.
Key Concepts:
 Whole numbers are either even or odd. Even numbers are the sum of 2 equal whole addends, and odd numbers are not.
 We can count by twos or pair objects to determine whether there is an odd or even number in a group.
 We can write an equation to show that a whole number is the sum of two equal addends.
Prior Knowledge Needed:
 Adding and subtracting whole numbers within 100; (Grade 1, Unit 1, 2; 1.OA.6 1.NBT.4)
 Doubling whole numbers; (Grade 1, Unit 1, 9; 1.OA.1 & 1.OA.6)
 Add up to four twodigit numbers using strategies based on place value and properties of operations. (Grade 2, Unit 11; 2.NBT.B.6)
 Compose & decompose numbers from 1119 (Kindergarten, Unit 14; K.NBT.A.1)
 Whole numbers can be decomposed into other whole numbers. (Grade 1, Unit 6; 1.OA.C.6) or would it be (Kindergarten, Unit 6; K.OA.3).
 We can divide a whole number up into two groups or two addends by giving each group one item until there are no items left to share (Grade 1, Unit 6; 1.OA.C.6).
Units on the Horizon:
 Introduction to multiplication dana center unit title (Grade 3, Unit 1; 3.OA.1)
 Introduction to division (Grade 3, Unit 1; 3.OA.1)
Lessons

Lesson objective: Understand that a whole number is either even or odd; an even number can be decomposed into two equal groups, while an odd number cannot. Students use prior knowledge of decomposing whole numbers from Grade 1, Unit 6, 1.OA.C.6. This pr...

Lesson objective: Decomposing whole numbers to determine if they are even or odd. This lesson helps to build fluency with identifying even and odd whole numbers. Decomposing each whole number into two groups is used here as a strategy for determining ev...

Lesson objective: Sort even and odd numbers by composing and decomposing a whole number of their choice. This lesson provides an opportunity for students to apply their knowledge and understanding of even and odd numbers to a reallife situation of sort...

Lesson objective: Counting by twos or pairing objects to determine if a set of objects is even or odd. Students bring prior knowledge of decomposing numbers into pairs in more than one way from Kindergarten, Unit 10, K.OA.3. This prior knowledge is exte...

Lesson objective: Identify even and odd numbers by pairing objects or counting by twos. This lesson helps to build understanding of how to identify even and odd numbers by utilizing the strategies of counting by twos and pairing objects. A game with cou...

Lesson objective: Identify if a whole number is even or odd by decomposing it into groups and utilizing the strategies of counting by twos and pairing. This lesson provides an opportunity for students to apply their knowledge and understanding of even a...

Lesson objective: Writing equations to show that an even whole number is the sum of two equal addends. Students bring prior knowledge of decomposing whole numbers from Grade 1, Unit 6, 1.OA.C.6 and Grade Kindergarten, Unit 10, K.OA.3. This prior knowled...

Lesson objective: Write an equation to prove if a number is even or odd. This lesson helps to build fluency with recognizing equations that represent even and odd sums. Equations are used here because it supports the decomposition of whole numbers to de...

Lesson objective: Analyze equations to determine if a number is even or odd. This lesson helps to build fluency with recognizing if an equation results in an even or odd sum. A game format highlighting playing cards with equations is used here because i...

Lesson objective: Decompose whole numbers to determine if they are even or odd. This lesson provides an opportunity for students to apply their knowledge and understanding of even and odd whole numbers to a reallife situation. Students are asked to dec...