Elementary Mathematics
1ST GRADE  UNIT 6: Number Games and Crayon Puzzles

Begin with the End in Mind..
common core expectations...


Students continue their work with true and false equations in2.6A. This is a concept that should be continuously reviewed with students, as it is an important part of the algebraic reasoning students will use in later grades. Students can consider true and false equations with Valid Equalities and other similar number talks.

Students work on decomposing numbers in Unit 6. The tasks in Investigations focus mostly on 2-addend situations. However, first grade students are required to work with addition equations with 3 parts too (1.OA.2). Daisies in Vases challenges students to arrange 8 daisies in 3 vases. Students can be challenged to fit the most daisies into the largest vase and the least daisies into the smallest vase. 

*** Click for UNIT 6 replacement pages for Student Activity Books


Suggested Dates:
January 28- March 3

Estimated Duration: 23 Days

Investigation 1: 9 lessons including session 1.8A and 1.8B .

Investigation 2: 6 including session 2.6A lessons .

Investigation 3: 8 lessons

Smart Board, PowerPoint, and Promethean Files

Smart Board Files:

 Unit 6 Smart Board File with Common Core additions

Daily Weather Notebook File


1st Grade Investigations Extension Projects

1st Grade Story Problem Routine

Investigations K-2 Literature List

Interactive Number Line

Interactive balance for exploring true and false equations

Story problem cards for Add To Change Unknown and Take From Change Unknown problems (reference page 6 of the Unpacking Document for a breakdown of story problem types).

End of Unit Rubrics 1st Grade

Unit 6 Vocabulary

Choice Board Unit 6 Lessons

End of Unit Rubrics 1st Grade

Unit 6 Vocabulary

Choice Board Unit 6 Lessons

This site provides an extensive collection of free resources, math games, and hands-on math activities aligned with the Common Core State Standards for Mathematics.

1st Grade At a Glance

Progression for choosing numbers for tasks


Suggestions for students who are struggling...

Continue to allow struggling students to work with smaller numbers (within 5, then 7, and then 10) until they demonstrate mastery with each number.  Emphasize using counters to act out and represent the problem situation.

Give students practice identifying, building, and combining quantities on the Five Frame.

Model equivalent expressions on an equibeam, in balances (either in the classroom on using pictures on a drawing of a balance), or on tens and twenties frames.

Encourage students to model combinations of 10 on the tens frame and verbalize how they found the missing addend with Sums of Ten.

Use smaller numbers for Crayon Puzzles.

Provide students with 2 color counters or manipulatives to use.

Use intervention strategies in Investigations manual. Suggestions are located throughout the chapter.


MP7. Look for and Make use of Structure
As students are working on combination problems, what questions can you ask to help them see the various ways to decompose a number?

Students return to crayon puzzles in Investigation 2. They should look for patterns to help them find all possible combinations of a number (for example, students can notice that as one addend increases by one, the other addend decreases by one). Ask, “How can you organize your work to make sure you have all possible combinations?”

MP8. Look for and express regularity and repeated reasoning.
While working on combination problems, how can we help students to understand that after finding one way to decompose a number (e.g, 8 = 4+4), other solutions can be found by increasing one addend by an amount and decreasing the other addend by the same amount (e.g, changing the addends by 1 results in 8=5+3, changing the addends by 2 results in 8=6+2).

MP4. Model with Mathematics

As students are working through these games, how can you support connections between their work and the writing of equations?

Students continue to represent everyday situations with equations and models in Unit 6. The discussions at the start and end of lessons focus on strategies for addition and subtraction and on writing matching equations. Many first grade students become confused when initially representing a subtraction situation. They often reverse the numbers, since they can reverse the parts in an addition equation without changing the meaning. Connect each number and symbol to characters and actions in story problems.


Students develop algebraic reasoning in Unit 6. One of the goals for students is to become flexible with the equal sign and to be able to determine the unknown number in a variety of positions (for example, ? + 6 = 10, 10 - ? = 6, or 10 = ? + 6). Read page 141, “About the Equal Sign” and “Children’s Understanding of Equality: A foundation for Algebra” and discuss, “What do first grade students need to understand about the equal sign? How does this help students as they further develop algebraic reasoning?”

P. 16- Algebra Connections in this Unit

P. 139- About the Equal Sign

P. 143- Strategies for Learning the Addition combinations

P. 145- About How many of each?

P. 179 and 181- Dialogue Box about supporting problem solving through read alouds.

Suggestions for students who fully understand...

Present students with story problems that involve 3 numbers, multiple steps and/or multiple solutions.

Challenge students to find multiple ways to make false equations true.

Encourage students to practice the relationship between addition and subtraction by creating fact family triangles. Then have students write and solve story problems that could be solved using their fact family equations.

Increase the number of crayons in the crayon puzzle. 

Add a third color for crayon puzzles, but keep the number of crayons within 10 to reduce the number of possible solutions.

Use enrichment strategies in Investigations manual.  Suggestions are located throughout the chapter.

Interactive Math Dictionary Site for Kids

Illuminations- Ten Frame activity
*Remember to upload files to share with others, or locate files to use, on the wiki. Be sure to join discussion posts with other colleagues to ask questions, answer questions, and discuss math.

Click here for the NCDPI CCSS Unpacking Document

This unit focuses on the Operations and Algebraic thinking strand. For more information about this strand and how it should look in the classroom, please visit the Common Core State Standards video series or the link to the unpacking document.

Represent and solve problems involving addition and subtraction.
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.

Understand and apply properties of operations and the relationship between addition and subtraction.
1.OA.3. Apply properties of operations as strategies to add and subtract.2 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.4. Understand subtraction as an unknown-addend problem. For example, subtract 10 – 8 by finding the number that makes 10 when added to 8. Add and subtract within 20.

Add and subtract within 20.
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 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).

Work with addition and subtraction equations.
1.OA.7. Understand the meaning of the equal sign, and determine if equations involving addition and subtraction are true or false. For example, which of the following equations are true and which are false? 6 = 6, 7 = 8 – 1, 5 + 2 = 2 + 5, 4 + 1 = 5 + 2.

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 = _.


Addition, Break apart (decompose), Equation, Equal, Join, More,
Minus, Counting on, Counting all, Counting up, Counting back, Put together (compose), Separate, Subtraction

Unit 6 requires students to Model with Mathematics. They must read, interpret, and represent a variety of story problems. View “Rigor Breakdown – Library Problem” and consider how the teacher prompts students to verbalize their models. Encourage students to use the vocabulary term “model” to help them understand that their numbers represent the situations described in the story problems.

Students need to be able to express how they found the missing number in an equation.
Put students in partners and teach children to play Find the Missing Number. Give students a board with the prompt, “I can use ______ because ____.” Then circulate. Help students identify the strategy they are using to add and subtract. Give them the sentence starter, “I used ______ (strategy). I ______ (walk through the procedure used). Reference pages 6-15 of the Unpacking Document for a description of strategies for addition and subtraction.

Investigation 1

As students work with combinations of 10, provide opportunities for them to work with concrete objects in the ten frame, pictures, and symbols, and make connections between the various representations. For example, when students are playing Three Towers and Tens Go Fish, showing their work through drawings and equations will support their understanding.
Investigation 2

n this Investigation students solve Crayon Puzzles. Using 2 color counters or actual crayon-shaped manipulatives will help students when they start this work. Encourage them to examine patterns and repeated reasoning by having them think about how they can change the quantities in one solution to find more solutions for that situation. For example, “We have 4 red and 4 blue crayons. What would happen if we traded a red crayon for a blue crayon? How many of each color would we have?”

Investigation 3

Students participate in a lot of subtraction work in this lesson. Reinforce the idea that subtraction can be thought of as a missing addend problem. Encourage them to think about counting on or counting back mentally or with a number line to support their work.
Quick Survey

Students continue their work with 1.MD.4.
Start With/
Get To:
Forward &

Students continue their work with the counting sequence. Remember the expectation is that students work within 120 by the end of the year. 

Quick Images

Students look at pictures of quantities using Ten Frames and reason about the value of each image.
Today's Number

Students consider different combinations of numbers that they can use to compose a larger quantity.
Morning Meeting

Students continue their work with the counting sequence, calendar, and patterns.