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# I have…you need

### What is it?

Explore relationships between partners of 5, 10, 20, 100, one-half, etc. while building number bonds.

### Why is it useful?

I have…You Need helps “kids construct important numerical relations.  Read more on Math is Figureoutable.

### Using “I Have…You Need” in Class

Time in Class: 10-15 minutes

#### Prior to the lesson: Create the questions

Choose a number to focus on. For example, you might focus on 100. Note: A natural progression is 10, 20, 100. Younger students might work on 5’s. Older grades might work on 1/2.

Create a progression of “I have…you need” statements to be used in the lesson. This progression can last over many days. You do not need to (should not) complete all of them in one session.

> Start with higher numbers that end in 0 (ie. I have 90. You need “10”). After writing a few, move on to the lower numbers ending in 0. (ie. I have 20. You need “80”).

> Move on to numbers ending in 5: higher numbers first, then lower numbers. After writing a few, you can also ask the reciprocal question right away. (ie. I have 85. You need “15”. I have 15. You need “85”.)

> Move on to numbers ending in 6 or 4. Write a helper question before each one. (ie. I have 85. You need “15”. I have 86. You need “14”.)

> Move on to any numbers within 100.

#### Implementation:

Explain the process. Your target number is “100”. You will say a number and give them a moment to think. When you point at the students, they will tell you what you need to make 100. Make the first statement. (ie. I have 80.) Wait a few seconds and then point to the class and say “You need”. Note: The more complex the number, the longer wait time you should provide.

After you have explored you list of questions with numbers ending in 0, repeat the questions but record them on the board. (ie. “When I said 80… Write “80 + …”You said”…Write 20…”Altogether that’s”….Write ” = 100″

Ask students to look at the equations on the board and look for patterns. What do they notice? (Do they notice that the number in the tens add to 10?)

Repeat this process for numbers ending in 5. What patterns do they notice? (Do they notice the number in the tens only adds to 9? Why is that?)

Repeat this process for numbers ending in 4/6. What patterns do they notice?

Repeat for all further questions.

Important Note: If students appear to be struggling, move to easier numbers. For example, if they are struggling with 2 digit numbers that end in 0, move back to number bonds of 20. If they are struggling with number bonds of 10, move back to number bonds of 10.  Provide enough time and experience for students to become comfortable with the numbers you are working on before moving on to more complex numbers.

### Examples of I have…you need

I have / You need

90 / 10

80 / 20

50 / 50

70 / 30

60 / 40

10 / 90

20 / 80

30 / 70

40 / 60

What patterns do you see?

95 / 5

5 / 95

85 /  15

15 / 85

75 / 25

25 / 75

65 / 35

35 / 65

55 / 45

45 / 55

What patterns do you see?

95 / 5

96 / 4

94 / 6

80 / 20

85 / 15

86 / 14

84 / 16

70 / 30

75 / 25

76 / 24

74 / 26

60 / 40

65 / 35

66 / 34

64 / 36

50 / 50

55 / 45

56 / 44

54 / 46

What patterns do you see?