Unit 2

Adding and Subtracting to 10

 

Grade 1

Math

 

Unit Length and Description:

 

Length: 6 weeks

 

Description: This unit focuses on the operations of addition and subtraction within 10, including the development of the part and whole relationships. The link between addition and subtraction is developed in this unit. Various strategies for addition and subtraction are used to develop fact fluency for addition and subtraction within 10.

 

Standards:

 

CCSS for Mathematical Content

CCSS #

CCSS Text

Operations and Algebraic Thinking

1.OA.1

Use addition and subtraction within 20 to solve word problems involving situations of adding to, take from, putting together, taking apart, and comparing, with unknowns in all positions, e.g., by using objects, drawings, and equations with a symbol for the unknown number to represent the problem.

1.OA.3

Apply properties of operations as strategies to add and subtract.  Examples:  If 8 + 3 = 11 is known, then 3 + 8 =11 is also known.  (Commutative property of addition.)  To add 2 + 6 + 4 = 2 + 10 = 12.  (Associative property of addition.)

1.OA.5

Relate counting to addition and subtraction (e.g., by counting on 2 to add 2).

1.OA.6

Add and subtract within 20, demonstrating fluency for addition and subtraction within 10.  Use strategies such as counting on; making 10 (e.g., 8 + 6 = 8 + 2 + 4 = 10 + 4 = 14); decomposing a number leading to a ten (e.g., 13 – 4 = 13 – 3 – 1 = 10 – 1 = 9); using the relationship between addition and subtraction (e.g., knowing that 8 + 4 = 12, one knows 12 – 8 =4); and creating equivalent but easier or known sums (e.g., adding 6 + 7 by creating the known equivalent 6 + 6 +1 = 12 + 1 = 13).

Standards for Mathematical Practice (MP)

MP.1

Make sense of problems and persevere in solving them

MP.2

Reason abstractly and quantitatively

MP.6

Attend to precision

MP.7

Look for and make use of structure

MP.8

Look for and express regularity in repeated reasoning

CCSS for ELA Content

Writing

W.1.2

Write informative/explanatory texts in which they name a topic, supply some facts about the topic, and provide some sense of closure.

W.1.8

With guidance and support from adults, recall information from experiences or gather information from provided sources to answer a question.

Speaking and Listening

SL.1.1

Participate in collaborative conversation with diverse partners about grade 1 topics and texts with peers and adults in small and larger groups.

a.  Follow agreed-upon rules for discussions (e.g., listening to others with care, speaking one at a time about topics and texts under discussion.)

b.  Build on others’ talk in conversation by responding to the comments of others through multiple exchanges.

c.  Ask questions to clear up any confusion about the topics and texts under discussion.

 

Instructional Outcomes

 

1.OA.1: Use addition and subtraction within 20 to solve word problems involving situations of adding to, take from, putting together, taking apart, and comparing, with unknowns in all positions, e.g., by using objects, drawings, and equations with a symbol for the unknown number to represent the problem.

  • I can use a symbol (e.g. ?, x) to represent an unknown number in a problem.
  • I can determine the operation to solve word problems with unknowns.
  • I can use different strategies for addition to solve word problems within 20.
  • I can use different strategies for subtraction to solve word problems within 20.
  • I can solve word problems by adding 3 numbers in different ways.

 

1.OA.3: Apply properties of operations as strategies to add and subtract.  Examples:  If 8 + 3 = 11 is known, then 3 + 8 =11 is also known.  (Commutative property of addition.)  To add 2 + 6 + 4 = 2 + 10 = 12.  (Associative property of addition.)

  • I can use fact families to help me solve addition problems. (commutative)
  • I can explain how properties of addition and subtraction work.
  • I can use strategies to solve addition and subtraction problems.

 

1. OA.5: Relate counting to addition and subtraction (e.g., by counting on 2 to add 2).

 

  • I can count on from a given number.
  • I can count back from a given number.
  • I can explain how counting on relates to addition.
  • I can explain how counting back relates to subtraction.
  • I can explain how counting on relates to subtraction.

 

1.OA.6: Add and subtract within 20, demonstrating fluency for addition and subtraction within 10.  Use strategies such as counting on; making 10 (e.g., 8 + 6 = 8 + 2 + 4 = 10 + 4 = 14); decomposing a number leading to a ten (e.g., 13 – 4 = 13 – 3 – 1 = 10 – 1 = 9); using the relationship between addition and subtraction (e.g., knowing that 8 + 4 = 12, one knows 12 – 8 =4); and creating equivalent but easier or known sums (e.g., adding 6 + 7 by creating the known equivalent 6 + 6 +1 = 12 + 1 = 13).

  • I can add within 20.
  • I can subtract within 20.
  • I can use strategies to add and subtract within 20.
  • I can add fluently within 10.
  • I can subtract fluently within 10.

 

1.OA.8: Determine the unknown whole number in an addition or subtraction equation relating three whole numbers. For example, determine the unknown number that makes the equation true in each of the equations 8 + ? = 11, 5 = _ – 3, 6 + 6 = _.

  • I can recognize part-part-whole relationships of three numbers
  • I can figure out the missing value in an addition equation.
  • I can figure out the missing value in a subtraction problem.

 

 

 

Enduring Understandings:

 

·         Students will understand the relationship between addition and subtraction. 

·         Students will understand the part and whole relationships within numbers. 

·         Students will compose and decompose the numbers 1 to 10. 

·         Students will solve various types of word problems using objects, drawings, and symbols. 

·         Students will develop fact fluency for addition and subtraction within 10.

 

Essential Questions:

 

·         How do we show that numbers work together?

·         How can we show and explain our thinking?

·         How does understanding numbers help me?

·         How do drawing pictures and words help me understand numbers?

·         How can a problem be solved in different way?