25
Add and Subtract Integers Learning Objective: We will add and subtract positive and negative integers. Math NS 1.3

Add and Subtract Integers Learning Objective: We will add and subtract positive and negative integers. Math NS 1.3

Embed Size (px)

Citation preview

Page 1: Add and Subtract Integers Learning Objective: We will add and subtract positive and negative integers. Math NS 1.3

Add and Subtract Integers

Learning Objective: We will add and subtract positive and negative integers.

Math NS 1.3

Page 2: Add and Subtract Integers Learning Objective: We will add and subtract positive and negative integers. Math NS 1.3

What do we already know?

• Positive integers are on the right side of zero. 4

• Negative integers are on the left side of zero. -4

• This means that they are opposites. -3 + 3 = 0

PositiveNegative

Page 3: Add and Subtract Integers Learning Objective: We will add and subtract positive and negative integers. Math NS 1.3

5 + -2 =3

5

-2

You know how to plot an expression on the number line and find the sum.

Step 1: Plot the first integer on the number line.Step 2: Plot the second integer on the number line beginning where the last number left off.

Page 4: Add and Subtract Integers Learning Objective: We will add and subtract positive and negative integers. Math NS 1.3

You know how to plot an expression on the number line and find the difference.

5 + -2=

5

-2

3

Step 1: Plot the first integer on the number line.Step 2: Plot the second integer on the number line beginning where the last number left off.

Page 5: Add and Subtract Integers Learning Objective: We will add and subtract positive and negative integers. Math NS 1.3

You know how to plot an expression on the number line and find each sum.

-3 + -1 =- 4

-1 -3

Step 1: Plot the first integer on the number line.Step 2: Plot the second integer on the number line beginning where the last number left off.

Page 6: Add and Subtract Integers Learning Objective: We will add and subtract positive and negative integers. Math NS 1.3

You already learned that subtracting a negative integer

gives the same solution as adding its opposite.

Page 7: Add and Subtract Integers Learning Objective: We will add and subtract positive and negative integers. Math NS 1.3

Vocabulary

• Define integers: a positive or negative number.

• Define a positive integer: whole numbers to the left of zero.

• Define a negative integer: whole numbers to the right of zero.

positivenegative

Page 8: Add and Subtract Integers Learning Objective: We will add and subtract positive and negative integers. Math NS 1.3

Vocabulary

Define absolute value: the distance from zero.

Plot each of the integers below on a number line and then tell the absolute value of

each. -1 2 -5

QuickTime™ and a decompressor

are needed to see this picture.

(1) (2) (5)

-1

2-5

Page 9: Add and Subtract Integers Learning Objective: We will add and subtract positive and negative integers. Math NS 1.3

You already learned that subtracting a negative integer

gives the same solution as adding its opposite.

To help predict whether the sum of two integers will be positive or

negative, you can use these rules.

Page 10: Add and Subtract Integers Learning Objective: We will add and subtract positive and negative integers. Math NS 1.3

1st Variation

Is the sum of 2 and 7 positive or negative?Rule: The sum of two positive integers is positive.

2+7=

Solution: The sum of 2 and 7 is positive.

2 7

9Step 1: Change the expression to an addition by using the absolute value.Step 2: Plot the first integer on the number line.Step 3: Plot the second integer on the number line beginning where the last number left off.

Page 11: Add and Subtract Integers Learning Objective: We will add and subtract positive and negative integers. Math NS 1.3

2nd Variation

Is the sum of -2 and -7 positive or negative?Rule: the sum of two negative integers is negative.

-2 + -7=

Solution: The sum of -2 and -7 is negative.

-2-7

-9Step 1: Change the expression to an addition by using the absolute value.Step 2: Plot the first integer on the number line.Step 3: Plot the second integer on the number line beginning where the last number left off.

Page 12: Add and Subtract Integers Learning Objective: We will add and subtract positive and negative integers. Math NS 1.3

3rd VariationIs the sum of -2 and 7 positive or negative?

Rule: the sum of a positive integer and a negative integer will have the same sign as the integer with the greater absolute value.

-2 + 7=

Solution: The sum of -2 and 7 is positive.

QuickTime™ and a decompressor

are needed to see this picture.

-2

7

5

Step 1: Change the expression to an addition by using the absolute value.Step 2: Plot the first integer on the number line.Step 3: Plot the second integer on the number line beginning where the last number left off.

Page 13: Add and Subtract Integers Learning Objective: We will add and subtract positive and negative integers. Math NS 1.3

Why is this important?

If the temperature was 10 ー F at lunch time and dropped to -5 ー F in the evening. What is the difference between these temperatures?

10 - -5= 15 degrees

Mauricio were at the corner store. Mauricio forgot his money and needs $10 to pay for his treats. IfOmar let Mauricio borrow $10, Mauricio now has$10. - $10 + $10 = 0

Page 14: Add and Subtract Integers Learning Objective: We will add and subtract positive and negative integers. Math NS 1.3

Guided Practice - I Do It

Rule: The sum of two positive integers is positive. 1 + 4=

1 4

5

Step 1: Change the expression to an addition by using the absolute value.Step 2: Plot the first integer on the number line.Step 3: Plot the second integer on the number line beginning where the last number left off.

Solution: The sum of 1 and 4 is positive.

Page 15: Add and Subtract Integers Learning Objective: We will add and subtract positive and negative integers. Math NS 1.3

Guided Practice - We Do It

Rule: The sum of two positive integers is positive. 5 + 3=

5 3

8

Step 1: Change the expression to an addition by using the absolute value.Step 2: Plot the first integer on the number line.Step 3: Plot the second integer on the number line beginning where the last number left off.

Solution: The sum of 5 and 3 is positive.

Page 16: Add and Subtract Integers Learning Objective: We will add and subtract positive and negative integers. Math NS 1.3

Guided Practice - You Do It

Rule: The sum of two positive integers is positive. 7 + 3=

7 3

10

Step 1: Change the expression to an addition by using the absolute value.Step 2: Plot the first integer on the number line.Step 3: Plot the second integer on the number line beginning where the last number left off.

Solution: The sum of 7 and 3 is positive.

Page 17: Add and Subtract Integers Learning Objective: We will add and subtract positive and negative integers. Math NS 1.3

Guided Practice - I Do It

Rule: the sum of two negative integers is negative.

-2 + -3=

-2-3

-5 Step 1: Change the expression to an addition by using the absolute value.Step 2: Plot the first integer on the number line.Step 3: Plot the second integer on the number line beginning where the last number left off.

Solution: The sum of -2 and -3 is negative.

Page 18: Add and Subtract Integers Learning Objective: We will add and subtract positive and negative integers. Math NS 1.3

Guided Practice - We Do It

Rule: the sum of two negative integers is negative.

-1 + -4=

-1-4

-5Step 1: Change the expression to an addition by using the absolute value.Step 2: Plot the first integer on the number line.Step 3: Plot the second integer on the number line beginning where the last number left off.

Solution: The sum of -1 and -4 is negative.

Page 19: Add and Subtract Integers Learning Objective: We will add and subtract positive and negative integers. Math NS 1.3

Guided Practice - You Do It

Rule: the sum of two negative integers is negative.

-4 + -6=

-4-6

-10Step 1: Change the expression to an addition by using the absolute value.Step 2: Plot the first integer on the number line.Step 3: Plot the second integer on the number line beginning where the last number left off.

Solution: The sum of -6 and- 4 is negative.

Page 20: Add and Subtract Integers Learning Objective: We will add and subtract positive and negative integers. Math NS 1.3

Guided Practice - I Do It

Rule: the sum of a positive integer and a negative integer willhave the same sign as the integer with the greater absolute value. 4 - -2= 4 + 2=

6

4 2

Step 1: Change the expression to an addition by using the absolute value.Step 2: Plot the first integer on the number line.Step 3: Plot the second integer on the number line beginning where the last number left off.

Solution: The difference of 4 and -2 is positive.

Page 21: Add and Subtract Integers Learning Objective: We will add and subtract positive and negative integers. Math NS 1.3

Guided Practice - We Do It

Rule: the sum of a positive integer and a negative integer will have the same sign as the integer with the greater absolute value. 4 - -6=

4 + 6=

4 6

10Step 1: Change the expression to an addition by using the absolute value.Step 2: Plot the first integer on the number line.Step 3: Plot the second integer on the number line beginning where the last number left off.

Solution: The difference of 4 and -6 is positive.

Page 22: Add and Subtract Integers Learning Objective: We will add and subtract positive and negative integers. Math NS 1.3

Guided Practice - You Do It

Rule: the sum of a positive integer and a negative integer will have the same sign as the integer with the greater absolute value. 3 - -7=

3 + 7 =

3 7

Step 1: Change the expression to an addition by using the absolute value.Step 2: Plot the first integer on the number line.Step 3: Plot the second integer on the number line beginning where the last number left off.

Solution: The difference of 3 and -7 is positive.

10

Page 23: Add and Subtract Integers Learning Objective: We will add and subtract positive and negative integers. Math NS 1.3

Closure• What is a whole number to the right of zero? • It is a positive integer.

• What is a whole number to the left of zero?• It is a negative integer

• What is the distance from zero?• It is the absolute value.

QuickTime™ and a decompressor

are needed to see this picture.

Negative Positive

Page 24: Add and Subtract Integers Learning Objective: We will add and subtract positive and negative integers. Math NS 1.3

Closure

Decide if the sum or difference is positive or negative.

Explain how you decided.

Solve the expression.

-10 + -6 = 8 - -6=

Share with your partner one thing that you learned today.

Page 25: Add and Subtract Integers Learning Objective: We will add and subtract positive and negative integers. Math NS 1.3

QuickTime™ and a decompressor

are needed to see this picture.

Step 1: Change the expression to an addition by using the absolute value.Step 2: Plot the first integer on the number line.Step 3: Plot the second integer on the number line beginning where the last number left off.