Making a Ten
Lesson 7 of 8
Objective: Students will be able to find the sums of addition problems by first making a ten, then adding.
Activator and Materials
I begin the lesson by discussing what Friends of Ten Facts are. Remind students that a Friend of Ten fact is going to be a fact with two addends that add up to ten. Introduce the students to the Friends of Ten video. Have the students then create a list of all of the friends of ten facts.
Continue the lesson by writing the following number sentence on the board.
Have the students solve the problem and then turn and talk about the ways that they could solve this problem and what strategies they have learned that would help them solve it. If necessary, guide the students to think about adding the 7 and 3 first to make a ten.
Why would it be helpful to start by adding the two numbers together that would make a ten? Review with the students that when you add any one-digit number to a ten you simply replace the zero in the ones place with the digit you’re adding. The Common Core standards encourages students to think about and explain how addition strategies work. This gives the students an opportunity to think about why these strategies can be helpful.
Develop the Concept
Have the students do some exploring with the Double Ten Frame mat. Have them turn and talk about what they notice. I always instruct my students that they should be able to recognize that a full ten frame is always going to equal ten, just as two hands with all their fingers held up will always equal ten. We repeat this idea as a “silent scream” many times over the course of the year. I want the students to commit that visual model to memory. I also find it helpful to have students notice that the top row of a ten frame is always five, similar to the idea that one hand with all fingers up will always be five. From fingers, to ten frames, students are building visualization skills so that they can move to bare numbers and rote calculation and still have understanding.
Write the number 7+ 9 = _____ on the board. Using a Double Ten frame, instruct students to build the first addend, 7, on the top ten frame and the second addend, 9, on the bottom ten frame. Remind the students that a full ten frame is always going to equal a ten.
Ask the students to turn and talk about a way that they could make a full ten frame from these numbers. If necessary, guide the students to think about moving some of the chips from one ten frame to the other to make a full ten frame. Ask the students to think about which one they would move. I tell my students that it doesn’t matter which chips they move, but that it would make the most sense to fill the ten frame that is already the closest to being a full ten frame. In this problem, it would be the 9. Then ask the students to move their chips.
It is important to explore the new configuration, because their ten frame no longer represents the problem 7 + 9. What do you notice about the double ten frame? Does the frame still show the problem 7 + 9? Students turn and talk about what new addition problem is being represented (10+6).
Practice the Concept
Have the students continue to practice this idea with the practice problems. Even if some students may not need the ten frame tool, all students build the addition sentence on their ten frame, move the counters to make a full ten frame, and rewrite the problem.
It is important for the students to understand that they need to build each problem. It is not that they couldn’t solve the problem with some other strategy, but that we are practicing this strategy.
Have students come back together as a class.
Today you made ten to add. Discuss with your partner if making ten is a good addition strategy.
Have the students think about how they could use this strategy when solving word problems. How could this strategy help when solving a math problem mentally?