REPRESENTING SUBTRACTION A NUMBER

LINEAdd the opposite

Bell Ringer

What is subtraction?

Where we were…

Opposites, Zero Pairs, Additive Inverse

Commutative Property of Addition

Rules for Adding Integers…

Where we are…

Unit Plan Students will learn to…

Discuss strategies for adding integers.

Compare and contrast subtraction and addition of integers.

Strategies for Adding Integers

Number Line

Context Money Football Others?

Rules Adding like signs Adding opposite signs

Is p – q = p + (-q)

Explain

Group Activity

Write down the problem assigned to your group.

Solve using a number line. Compare with others in your group.

Compare with someone in your partner group.

Discuss the questions.

Model on a Number Line

Group 1: 8 – 3

Group 2: 7 – 13

Group 3: -15 - 6

Group 4: 8 + (-3)

Group 5: 7 + (-13)

Group 6: -15 + (-6)

Write the problem above your number line.

Compare with Other Group

GROUPS 1 and 4 2 and 5 3 and 6

Discussion Questions: How are your problems

similar? How are they different? What previous vocabulary is

used?

Model on a Number Line

Group 1: 8 – 3

Group 2: 7 – 13

Group 3: -15 - 6

Group 4: 8 + (-3)

Group 5: 7 + (-13)

Group 6: -15 + (-6)

Changing Subtraction to Addition

8 – 3 8 + (-3)

7 – 13 7 + (-13)

- 15 – 6 -15 + (-6)

- 2 – (-9)

- 2 + 9

Add the Opposite

Is p – q = p + (-q)

Explain

Subtraction Strategies

Use a number Line

Use context Money Football Others?

“Add the Opposite” and use rules for addition

Homework

Check homework

Quiz

Homework

Integer Investigation

SHOW ALL STEPS

Pick one of the strategies and use it… Pictures Number Line Rules Context

Exit Ticket

When would using a number line to model addition or subtraction of integers not be an efficient strategy?

1 minute – talk with your partner

2 minutes – Power Write

Bell Ringer

When would using a number line to solve addition or subtraction of integers not be an efficient strategy?

Where we were… Addition Strategies

Number line Context Rules

Same signs – add and keep the signs Opposite signs – subtract, keep sign of # w/

largest absolute value. Subtraction strategies

Number Line Context “add the opposite” and use rules for addition

Where we are…

Students will learn to…

Review the strategies used for adding and subtracting integers.

Practice

On Jeopardy, Jill answered one question correctly for 400. She then answered two questions incorrectly, one for 100 and the other for 200.

Write an ADDITION expression to represent the situation.

Write a SUBTRACTION expression to represent the situation.

How many total points did Jill have?

Practice On Jeopardy, Jill answered one question

correctly for 400. She then answered two questions incorrectly, one for 100 and the other for 200.

Write an ADDITION expression to represent the situation. 400 + (-100) + (-200)

Write a SUBTRACTION expression to represent the situation. 400 – 100 - 200

How many total points did Jill have? 100

Practice

A deep sea diver saw his jelly fish at 12 feet below sea level. He dove down another 20 feet before he finally saw another jelly fish.

Write an ADDITION expression that shows this scenario.

Write a SUBTRACTION expression to represent the situation.

What was the total depth of the diver?

Practice A deep sea diver saw his jelly fish at 12

feet below sea level. He dove down another 20 feet before he finally saw another jelly fish.

Write an ADDITION expression that shows this scenario. -12 + (-20)

Write a SUBTRACTION expression to represent the situation. -12 - 20

What was the total depth of the diver? -32 ft

Practice

John owed his mom $40 for a new pair of shoes. He then borrowed $15 for a new DVD.

Write a SUBTRACTION expression that shows this scenario.

How much money does John owe?

Practice

John owed his mom $40 for a new pair of shoes. He then borrowed $15 for a new DVD.

Write a SUBTRACTION expression that shows this scenario.

-40 – 15 -40 + (-15)

How much money does John owe? -$55

Homework

Write an expression for each problem.

Solve any way you choose.

Label your answer.