Adding integers

Addition of Integers

I can add positive and negative I can add positive and negative numbers.numbers.

What is the rule for adding What is the rule for adding integers with the same signs? integers with the same signs?

Different signs?Different signs?

Pair SharePair Share

Read your Quickwrite to your partner.Read your Quickwrite to your partner.

Rule: Rule: To add numbers with the same sign, To add numbers with the same sign,

ADD the numbers.ADD the numbers.KEEP THE SIGN of the numbers involved.KEEP THE SIGN of the numbers involved.

To add numbers with opposite signs To add numbers with opposite signs Subtract the numbers. Subtract the numbers. Keep the sign of the number with the Keep the sign of the number with the

larger absolute value.larger absolute value.

Lesson: Posing a QuestionLesson: Posing a Question

2 min. 2 min. ““Think TimeThink Time””Work out the problem using any strategy.Work out the problem using any strategy.Write down facts you know about the Write down facts you know about the

problem.problem.I know…I know…I need to find out…I need to find out…

Come up with questions you might have.Come up with questions you might have.You do not have the option to just sit there!You do not have the option to just sit there!

5 + 3 =

-5 + (-3) =

5 + 3 = 8 Up 5 , then up 3 more If you have $5 in your pocket and are given $3 more, how much do you have?

-5 + (-3) = -8 Down 5 then down 3 moreIf you owe $5 and then borrow $3 more, how much do you have?

5 + -3 =

-5 + 3 =

5 + -3 = 2 Up 5 , then down 3If you have $5 in your pocket and borrow $3 more, how much do you have?

-5 + 3 = -2 Down 5 then up 3If you owe $5 and then pay back $3, how much do you owe?

A submarine was situated 800 feet A submarine was situated 800 feet below sea level. If it ascends(goes up) below sea level. If it ascends(goes up) 250 feet, what is its new position?250 feet, what is its new position?

Write an ADDITION EXPRESSION, then Write an ADDITION EXPRESSION, then solve. Justify your response.solve. Justify your response.

A submarine was situated 800 feet A submarine was situated 800 feet below sea level. If it ascends(goes up) below sea level. If it ascends(goes up) 250 feet, what is its new position?250 feet, what is its new position?

-850 + 250 = -600 feet-850 + 250 = -600 feet

You enter the elevator on the 8You enter the elevator on the 8thth floor. floor. The elevator goes up 5 floors, and then The elevator goes up 5 floors, and then goes down 7 floors . What floor are you goes down 7 floors . What floor are you on? on?

Write and evaluate and addition Write and evaluate and addition expression to find the floor on which you expression to find the floor on which you exit.exit.

You enter the elevator on the 8You enter the elevator on the 8thth floor. floor. The elevator goes up 5 floors, and then The elevator goes up 5 floors, and then goes down 7 floors . What floor are you goes down 7 floors . What floor are you on? on?

Write an evaluate and addition expression Write an evaluate and addition expression to find the floor on which you exit.to find the floor on which you exit.

8 + 5 + (-7) = 6 68 + 5 + (-7) = 6 6thth floor floor

A football team gained 5 yards on the first A football team gained 5 yards on the first play, then they lost 7 yards on the second play, then they lost 7 yards on the second play, but gained 9 yards on the third play. play, but gained 9 yards on the third play.

To get a first down, they must gain 10 To get a first down, they must gain 10 yards in 4 plays.yards in 4 plays.

How many yards must they gain on the 4How many yards must they gain on the 4thth play to get a first down?play to get a first down?

Write an addition expression and solve.Write an addition expression and solve.

A football team gained 5 yards on the first A football team gained 5 yards on the first play, then they lost 7 yards on the second play, then they lost 7 yards on the second play, but gained 9 yards on the third play. play, but gained 9 yards on the third play.

To get a first down, they must gain 10 yards To get a first down, they must gain 10 yards in 4 plays.in 4 plays.

How many yards must they gain on the 4How many yards must they gain on the 4thth play to get a first down?play to get a first down?

Write an addition expression and solve.Write an addition expression and solve. 5 + (-7) + 9 = 7 so they need 3 more yd5 + (-7) + 9 = 7 so they need 3 more yd

Integer Rule SheetInteger Rule Sheet

Put your first and last name on it and DO Put your first and last name on it and DO NOT lose this sheet.NOT lose this sheet.

Using VariablesUsing Variables

Adding IntegersAdding IntegersEvaluate when Evaluate when x = - 5, y = 20, z = - 3x = - 5, y = 20, z = - 3

y + xy + x

x + (-z)x + (-z)

-x + | y |-x + | y |

Using VariablesUsing Variables

Adding IntegersAdding IntegersEvaluate when Evaluate when x = - 5, y = 20, z = - 3x = - 5, y = 20, z = - 3

y + xy + x

x + (-z)x + (-z)

-x + | y |-x + | y |

20 + -5 = 15

-5 + 3 = -2

5 + 20 = 25

Apply the rules:Apply the rules:

-8 + -12 = ___ 5 + -9 = _____-8 + -12 = ___ 5 + -9 = _____

-6 + 15 = _____ - 4 + -3 + -7 = _____-6 + 15 = _____ - 4 + -3 + -7 = _____

7 + 5 = _____ -5 + 3 + 5 + -8 = ___7 + 5 = _____ -5 + 3 + 5 + -8 = ___

-7 + 7 = ____-7 + 7 = ____ -13 + 0 =____-13 + 0 =____

Apply the rules:Apply the rules:

-8 + -12 = ___ 5 + -9 = _____-8 + -12 = ___ 5 + -9 = _____

-6 + 15 = _____ - 4 + -3 + -7 = _____-6 + 15 = _____ - 4 + -3 + -7 = _____

7 + 5 = _____ -5 + 3 + 5 + -8 = ___7 + 5 = _____ -5 + 3 + 5 + -8 = ___

-7 + 7 = ____-7 + 7 = ____ -13 + 0 =____-13 + 0 =____

-20 -4

9 -14

12

-130

-5

Rule: Rule: To add numbers with the same sign, To add numbers with the same sign,

ADD the numbers.ADD the numbers.KEEP THE SIGN of the numbers involved.KEEP THE SIGN of the numbers involved.

To add numbers with opposite signs To add numbers with opposite signs Subtract the numbers. Subtract the numbers. Keep the sign of the number with the Keep the sign of the number with the

larger absolute value.larger absolute value.

Class notes

Page 65 #2-6, 24-26, 52,56Corrections

Assignment: Assignment:

Show work and Show work and NO CALCULATORSNO CALCULATORS