Unit 6

Foundations of Multiplication and Division

 

Grade 2

Math

 

 

Description: In Unit 6 students extend their understanding of a unit to build the foundation for multiplication and division wherein any number can be a unit. Making equal groups of “four apples each” establishes the unit “four apples” (or just four) that can then be counted: 1 four, 2 fours, 3 fours, etc. Relating the new unit to the one used to create it lays the foundation for multiplication: 3 groups of 4 apples equal 12 apples (or 3 fours is 12).

 

Louisiana Student Standards for Mathematics (LSSM)

 

Supporting Cluster: OA – Operations and Algebraic Thinking

Work with equal groups of objects to gain foundations for multiplication.

2.OA.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.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 sum of equal addends.

Additional Cluster: G - Geometry

Reason with shapes and their attributes.

2.G.2

 

Partition a rectangle into rows and columns of same-size squares and count to find the total number of them.

 

Enduring Understandings:

 

• There are similarities between skip counting and repeated addition.

• Repeatedly adding the same quantity, using a grouping picture, or forming a rectangular array are strategies for representing repeated addition equations.

·   Arrays one way of representing both repeated addition and skip counting.

• Explore and be able to explain even and odd numbers while using manipulatives.

• An even number can be decomposed into two equal addends.

• Double addition facts assist in recognizing even numbers.

 

Essential Questions:

 

·   How are odd and even number lines identified on the number line?

• How do I determine if a number is odd or even?

• What strategies can I use to tell if a number is odd or even?

• How are arrays and repeated addition related?

• How can rectangular arrays help us with repeated addition?

• How can we model repeated addition on the number line?

• How can we a model repeated addition equation with an array?

• How does skip counting help us solve repeated addition problems?

• What is an array?

·   What is repeated addition?