Topic Five: Addition Facts to 20

Pacing (Duration of Unit):


Desired Results

Transfer:
1. Makes sense of problems and persevere in solving them.
2. Reason abstractly and quantitatively.
3. Construct viable arguments and critique the reasoning of others.
4. Model with mathematics.
5. Use appropriate tools strategically.
6. Attend to precision.
7. Look for and make use of structure.
8. Look for and express regularity in repeated reasoning.
Established Goals:
  • 1.OA.1 Use addition and subtraction within 20 to solve word problems involving situations of adding to, taking 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.2 Solve word problems that call for addition of three whole numbers whose sum is less than or equal to 20, 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, the second two numbers can be added to make a ten, so 2 + 6 + 4 = 2 + 10 = 12. (Associative property of addition.)
  • 1.OA.6 Add and subtract within 20, demonstrating fluency for addition and subtraction within 10. Use mental strategies such as counting on; making ten (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).

Pre-Requisite Standards:
  • K.OA.2 Represent addition and subtraction with objects, fingers, mental images, drawings, sounds (e.g., claps), acting out situations, verbal explanations, expressions, or equations.
  • K.OA.3 Decompose numbers less than or equal to 10 into pairs in more than one way, e.g., by using objects or drawings, and record each decomposition by a drawing or equation (e.g., 5 = 2 + 3 and 5 = 4 + 1).
  • K.OA.5 Fluently add and subtract within 5.
  • 1.OA.1 Use addition and subtraction within 20 to solve word problems involving situations of adding to, taking 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" Statements:
  • I can use strategies to solve addition word problems.
  • I can use strategies to solve subtraction word problems.
  • I can solve word problems by adding 3 whole numbers.
  • I can use the commutative property of addition.
  • I can use the associative property of addition.
  • I can add facts within 20.
  • I can subtract facts within 20.
Big Ideas:

Basic Facts
Some strategies for basic facts use equivalence to transform calculations into simpler ones.

Properties
For a given set of numbers there are relationships, called properties, that are always true, and these are the rules that govern arithmetic and algebra.

Practices, Processes, and Proficiencies
Mathematics content and practices can be applied to solve problems.
Essential Questions:

  • What other strategies can be used to find addition facts?
Students will know...

Doubles facts can be associated with memorable real-world situations.
Basic addition facts that are near doubles can be found using a related doubles fact.
Sometimes the answer to one problem/question is needed to find the answer to another problem/question.
Some addition facts can be found by changing to an equivalent fact with 10.
Addition facts involving 9 can be changed to an equivalent fact with 10.
Addition facts involving 8 can be changed to an equivalent fact with 10.
Three numbers can be grouped and added in any order.
Numbers can be grouped in different ways to solve word problems with three addends.


Vocabulary:

doubles plus 1
doubles plus 2
Students will be skilled at...

Recognizing the doubles relationship and and use it as a strategy for remembering addition facts with two like addends.
Mastering addition facts where the addends are 1 apart.
Mastering addition facts where the addends are 2 apart.
Solving two-question problems by using the answer to the first question to answer the second question.
Mastering addition facts where one addend is close to 10.
Mastering addition facts where one addend is 9.
Mastering addition facts where one addend is 8.
Using the associative and commutative properties to add three numbers.
Solving word problems that call for addition of three whole numbers whose sum is less than or equal to 20.

Assessment Evidence

Performance Assessment:
Other Evidence:

Learning Plan

Learning Activities:

5-1 Doubles facts can be associated with memorable real-world situations.
5-2 Basic addition facts that are near doubles can be found using a related doubles fact.
5-3 Basic addition facts that are near doubles can be found using a related doubles fact.
5-4 Sometimes the answer to one problem/question is needed to find the answer to another problem/question.
5-5 Some addition facts can be found by changing to an equivalent fact with 10.
5-6 Addition facts involving 9 can be changed to an equivalent fact with 10.
5-7 Addition facts involving 8 can be changed to an equivalent fact with 10.
5-8 Three numbers can be grouped and added in any order.
5-9 Numbers can be grouped in different ways to solve word problems with three addends.
Resources: