## Sum Search

• Lesson
Pre-K-2
1

During this lesson, students practice addition facts (with sums of 5, 6, 7, and 8) in a concentration-game format using dominoes. Then they generate sums to given numbers using a calculator and record them on a hundreds chart and look for patterns.

In this lesson, students play a Dominoes game. Children who have never played dominoes should be introduced to the game. Begin in a whole-group setting by showing the students a set of Double 6 dominoes.

Encourage the students to describe what they notice as they look at the tiles.

From a set of dominoes, select those that have 5, 6, 7, or 8 total spots. Place them upside down in an array where the children can see them. Now call on one student at a time to turn over two dominoes.

When the student turns over dominoes with the same total number of spots (sum), the student keeps them.

If the dominoes have different sums, both dominoes are returned face down to their place in the array and another child is called on.

You may want to play this game twice and then suggest that children can play it in pairs at a later time.

Now display the Using Calculators and Hundred Boards Electronic Tool.

Alternatively, you may give the children calculators and Hundreds Charts.

Explain to students that they are to use the calculator to find the addend pairs that give a sum of 5, then to ring each sum in yellow on the hundreds chart. When the students have finished, ask them to ring sums of 6 in green, sums of 7 in black, and sums of 8 in brown. At an appropriate time, call the children together and ask them to describe any patterns that they notice on the hundreds board.

Now give the students individual Addition Charts and ask them to complete the cells for any facts that they know by heart.

This activity will help them focus on the addition facts they know and those they have yet to memorize.

When the students are ready, remind them of the order property and ask them what else they can cover if they know, for instance, 4 + 3. If they answer 3 + 4, tell them to cover that also. When they have finished, ask if they know something about adding 0. If they can tell you the sum is always the same as the other addend, have them complete all the sums in the first row and column. Encourage them to notice that only a few facts remain blank. Remind them that they need to practice these facts.

Assessment Options

1. The Questions for Students help students focus on their current level of understanding and of fact mastery.
2. Document student understanding and skills on the Class Notes recording sheet to help you focus on individual needs and strengths and provide appropriate additional learning opportunities.

Questions for Students

1. What addends sum to 8? To 7? To 6? To 5?

[8: 0+8, 1+7, 2+6, 3+5, 4+4]
[7: 0+7, 1+6, 2+5, 3+4]
[6: 0+6, 1+5, 2+4, 3+3]
[5: 0+5, 1+4, 2+3]

2. Look at the numbers that add to 7 on the table. Do you see any doubles? How about when you look at those that added to 8? To 6? Why is that?

[There are no doubles for 7, but there are for 8 and 6; Only even numbers can be achieved by adding doubles.]

3. What happens when we add 0 to a number?

[The sum does not change.]

Teacher Reflection

• Did most students remember the effects of adding by 0? Did most recall the doubles facts?
• Which students met all the objectives of this lesson? What extension activities are appropriate for those students?
• Which students are still having difficulty with the objectives of this lesson? What additional instructional experiences do they need?
• What will you do differently the next time that you teach this lesson?

### Learning Objectives

Students will:

• Generate the addition facts with sums of 5, 6, 7, and 8.
• Use a game to practice the addition facts with sums of 5, 6, 7, and 8.

### NCTM Standards and Expectations

• Understand the effects of adding and subtracting whole numbers.
• Develop and use strategies for whole-number computations, with a focus on addition and subtraction.
• Develop fluency with basic number combinations for addition and subtraction.
• Use a variety of methods and tools to compute, including objects, mental computation, estimation, paper and pencil, and calculators.

### Common Core State Standards – Mathematics

-Kindergarten, Algebraic Thinking

• CCSS.Math.Content.K.OA.A.5
Fluently add and subtract within 5.

• CCSS.Math.Content.1.OA.B.4
Understand subtraction as an unknown-addend problem. For example, subtract 10 - 8 by finding the number that makes 10 when added to 8.

• CCSS.Math.Content.1.OA.C.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).