Week 1
Lesson 1
What does it mean to add?
Students will learn/discover: 
• The definition of addition 
• What it means to add two numbers 
• How to combine sets 
Lesson 2
What does it mean to add?
Students will learn/discover: 
• The definition of addition 
• What it means to add two numbers 
• How to combine sets 
 Week 2
Lesson 3
How Many Ways?
Students will learn/discover:
• How to use multiple statements to find the same sum

Being able to model sums using various addend combinations helps students develop a form base for mental math, fact recognition, and number relationships.
Lesson 4
How Many Ways?
Students will learn/discover:
• How to use multiple statements to find the same sum

Being able to model sums using various addend combinations helps students develop a form base for mental math, fact recognition, and number relationships.
 Week 3
Lesson 5
Ten Frames Addition Within Twenty
Students will learn/discover:
• How to add within 20

Adding numbers within 20 combines early number skill such as one-to-one correspondence with the joining of values into one set. This fosters the ability to use mental math later with regard to sets of 10.
Lesson 6
Ten Frames Addition Within Twenty
Students will learn/discover:
• How to add within 20

Adding numbers within 20 combines early number skill such as one-to-one correspondence with the joining of values into one set. This fosters the ability to use mental math later with regard to sets of 10.

 Week 4
Lesson 7
Place Value Addition
Students will learn/discover:
• How to model addition problems using place values of ones,
tens, and hundreds

Being able to model numbers in the context of ones, tens, and hundreds helps students understand the importance of place value in computation and mental math. This skill is also important as students begin to add larger numbers in the base ten system.
Lesson 8
Place Value Addition
Students will learn/discover:
• How to model addition problems using place values of ones,
tens, and hundreds

Being able to model numbers in the context of ones, tens, and hundreds helps students understand the importance of place value in computation and mental math. This skill is also important as students begin to add larger numbers in the base ten system.
 Week 5
Lesson 9
Decomposing Numbers
Students will learn/discover:
• How to add numbers up to the sum of 20 using decomposing within 20

Adding numbers up to the sum of 20 using the method
of decomposing numbers in place value is key with larger
numbers, up to the millions, in upper elementary grades.
Linking place value to addition and decomposing numbers
is important in understanding the way addition is related to
other operations.
Lesson 10
Decomposing Numbers
Students will learn/discover:
• How to add numbers up to the sum of 20 using decomposing within 20

Adding numbers up to the sum of 20 using the method
of decomposing numbers in place value is key with larger
numbers, up to the millions, in upper elementary grades.
Linking place value to addition and decomposing numbers
is important in understanding the way addition is related to
other operations.
 Week 6
Lesson 11
Decomposing Numbers
Students will learn/discover:
• How to add numbers up to the sum of 20 using decomposing within 20

Adding numbers up to the sum of 20 using the method
of decomposing numbers in place value is key with larger
numbers, up to the millions, in upper elementary grades.
Linking place value to addition and decomposing numbers
is important in understanding the way addition is related to
other operations.
Lesson 12
Decomposing Numbers
Students will learn/discover:
• How to add numbers up to the sum of 20 using decomposing within 20

Adding numbers up to the sum of 20 using the method
of decomposing numbers in place value is key with larger
numbers, up to the millions, in upper elementary grades.
Linking place value to addition and decomposing numbers
is important in understanding the way addition is related to
other operations.
 Week 7
Lesson 13
Result Unkown Problems
Students will learn/discover:
• How to use a model to find the missing sum in a problem

Being able to model numbers helps students formulate an
understanding for number recognition. Ten-frames provide a
base for seeing more than and less than ten, which helps build
conceptual understanding about addition and subtraction.
Lesson 14
Result Unkown Problems
Students will learn/discover:
• How to use a model to find the missing sum in a problem

Being able to model numbers helps students formulate an
understanding for number recognition. Ten-frames provide a
base for seeing more than and less than ten, which helps build
conceptual understanding about addition and subtraction.
 Week 8
Lesson 15
Change Unknown Problems
Students will learn/discover:
• How to model problems with a missing addend in the
change location, which is the second addend or value in the
problem.

Modeling problems with missing addends in different locations
helps students understand the part-part-whole relationships
between numbers. In the change unknown problem, students
find the missing addend through a variety of strategies.
Lesson 16
Change Unknown Problems
Students will learn/discover:
• How to model problems with a missing addend in the
change location, which is the second addend or value in the
problem.

Modeling problems with missing addends in different locations
helps students understand the part-part-whole relationships
between numbers. In the change unknown problem, students
find the missing addend through a variety of strategies.
 Week 9
Lesson 17
Start Unknown Problems
Students will learn/discover:
• How to solve problems where the starting number in
the problem is unknown

Being able to model different types of addition problems is
key to understanding what strategies are best to utilize when
solving each type.
Lesson 18
Start Unknown Problems
Students will learn/discover:
• How to solve problems where the starting number in
the problem is unknown

Being able to model different types of addition problems is
key to understanding what strategies are best to utilize when
solving each type.
 Week 10
Lesson 19
Adding Large Numbers
Students will learn/discover:
• How to add numbers to sums within 100 using a place value method

Being able to add numbers that are sums within 100 begins the
process of adding even larger numbers. Linking place value to
addition and decomposing numbers is key to understanding
the way addition is related to other operations.
Lesson 20
Adding Large Numbers
Students will learn/discover:
• How to add numbers to sums within 100 using a place value method

Being able to add numbers that are sums within 100 begins the
process of adding even larger numbers. Linking place value to
addition and decomposing numbers is key to understanding
the way addition is related to other operations.