Math: Double Facts

(5) Patterns, relationships, and algebraic thinking. The student uses patterns in numbers and operations. The student is expected to:
- (C) use patterns and relationships to develop strategies to remember basic addition and subtraction facts. Determine patterns in related addition and subtraction number sentences (including fact families) such as 8 + 9 = 17, 9 + 8 = 17, 17 – 8 = 9, and 17 – 9 = 8.

Common Core State Standards

Operations and Algebraic Thinking, Grade 2

Understand and apply properties of operations and the relationship between addition and subtraction.

(3) Apply properties of operations as strategies to add and subtract.3 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.)
(4) Understand subtraction as an unknown-addend problem. For example, subtract 10 – 8 by finding the number that makes 10 when added to 8.

Operations and Algebraic Thinking, Grade 3

Solve problems involving the four operations, and identify and explain patterns in arithmetic.

(9) Identify arithmetic patterns (including patterns in the addition table or multiplication table), and explain them using properties of operations. For example, observe that 4 times a number is always even, and explain why 4 times a number can be decomposed into two equal addends.

Hook/Engage

Freeze Dance

“Today in math, we are going to start by playing a game. Is that what you usually do in math?” Students might say no. “Hm, well let’s try it anyways. In this game, I am going to play some music. You can dance while the music is playing, but when the music stops I want you to freeze. If we’re going to play a game, we have to make sure it’s a safe game, right? What might be some important things to think about for a game that asks you to dance or freeze?” Write down any ideas the students come up with. If they don’t say it, be sure to add, “I have a couple of ideas, too. Let’s keep our hands to ourselves and be sure to listen.” “These look like some great ideas that we could use during all of our time together. I’m going to leave it up here as a reminder of all of the things we agreed are important to remember while we explore dramai games together.”

Students play freeze dance to the song “I Can Add” (about doubles facts) by They Might Be Giants. As the music plays, the students dance any way that they want. During the first freeze explain, “Wow, you are all making shapes with your bodies. I see some big shapes, and small ones. I see round shapes and shapes on one foot.” Describe the shapes you see. Have students look at each other as you do this. “Look at Isa, she’s making a shape lying down.” Each time the music stops have the students freeze and make a shape. Start with any shape they want. Then add, “make a big shape,” then small ones, low to the ground ones. Each time the students freeze, they can make a different shape. Play this for a through the song, then stop the music. “That was so much fun. Were you listening to the song while you danced? Let’s see if we can remember the words together.” (The song is very catchy and repeats. “2+2 is 4, 4+4 is 8, 8+8 is 16, and 16+16 is 32…..”Then it is repeated in Spanish.) Speak through the doubles facts form the song with the students. “Do we know any other doubles facts? What about 3+3?” Explore the numbers not included in the song through 9. “Now we know our doubles facts so well, let’s play another game using doubles facts.”

Explore

The Truth About Me

“This game is called The Truth About Me. Let’s stand up in a circle. Make sure you have enough space around you so that you are not touching your neighbor. Let’s make sure we remember not to run and to take care of our friends while we play this game.” Give each student and teacher a number, 1-4, on a post it for them to wear on their top. Half way through the game, switch the numbers to 5-9. (This is so there are at least 3 students with each number.) Teacher will model this by standing in the center first. The person in the center (ie. if their number is 2) says, “The truth about me is my double is 4.” Each child who is the number 2 must find a new spot in the circle. One person will end in the center. After they have moved, the teacher repeats with the students, “2+2 is 4.” The person who ends in the center gets a new number. *Later variation, the center person could say, “The truth about me is I am the double of 1,” if they are the number 2.

Have the students sit down in a smaller circle. “Wow, we really got to know our doubles.” Or “We still have a lot to learn about doubles facts; that was fun.”

Number Balloons

“Let’s play another numbers game with music. We have to remember that we share this space with another class if we are going to do this, so we really have to listen to the music and keep it down a little, right?” Each student is given a balloon with a number, 1-9, written on it. Music plays (more from They Might Be Giants 1,2,3s) and the students try to keep the balloons in the air. When the music stops, each student catches a balloon. Students use +,- and = signs that are on the floor in construction paper to make math sentences together with the balloons they have caught and one of their math neighbors. For example, student A has a 2 and finds student B who has a 3. “2+3=5.”

Reflection

-“What did we do today?”

-“What are some doubles facts we learned today?”

-Ask for kids to raise their hands and answer “What is 1+1? 2+2?” etc.

-“Are there any ways you can think of that will help you remember these doubles facts in the future?” Remind students of the Freeze Dance.

“I had so much fun playing games with you today. Let’s look at that list of ideas we made at the beginning of class.” Review what is written on the list of ideas from Freeze Dance. “On a scale of 1-10, how did we do at remembering all of these things? How about the next time we meet, we try to make it a 10?”