Multiplication and Division of Integers

Re-write each as a sum

4 -5 = -1 4 + (- 5) = -1 -2 - (-3) = 1 -2 + 3 = 1

-14 - 5 = -19 -14 + (-5) = -19

12 - (-3) = 15 12 + 3 = 15

Rules for Multiplying Integers:

Multiplying two integers with the same signs:

Negative x negative = positive

Positive x positive = positive+ + +x =

+- -x =

Use the eraser to reveal the results.

Rules for Multiplying Integers:

Multiplying two integers with the different signs:

Negative x positive = negative

Positive x negative = negative+ - -x =

+- -x =

Use the eraser to reveal the results.

Try some.

- 5 x (-4) =- 5 x 4 =

6 x (-7) =

Find the products - move the positive and negative to remind you of the rule.

Positive +

Negative -

Rules for Dividing Integers:

Dividing two integers with the same signs:

Negative negative = negative

Positive positive = positive+ =

- -=

÷

÷+ +

÷ ÷

-

Use the eraser to reveal the results.

Rules for Dividing Integers:Use the eraser to reveal the results.

Dividing two integers with different signs:

Negative positive = negative

Positive negative = negative+ =

- -=

÷

÷

÷ ÷

- -

+

Try some.

-48 ÷ 6=

24 ÷ -6=

-63 ÷ -9=

Positive +

Negative -

Find the quotients - move the positive and negative to remind you of the rule!

+- -

Practice with Word Problems

Figuring an offensive team’s total yardage gained is not just a case of adding up the numbers.

Players make positive plays, such as yards gained rushing and yards gained passing.

They also make negative plays, such as yards lost rushing or yard lost on a quarterback sack.

There are also penalties; they work both ways.

Examine the following game situations and figure the total yards gained by the team.

Introduction:

The Washington Redskins gained 256 rushing yards in a game. They also lost 4 yards on one play. The quarterback threw for 154 yards, but he was sacked seven times. He lost a total of 53 yards on the sacks. How many total yards did the Redskins gain?

In one game the San Diego Chargers gained 187 yards rushing and 458 passing. But they had 211 yards of penalties against the offense.

How many total yards did they gain that night?

The New England Patriots are a passing team. They ran for only 47 yards last night, but they passed for 398. They lost 38 yards on sacks, and they had three offensive penalties against them for a total of 25 yards.

How many total yards did they gain last night?

The Oakland Raiders only gained 75 yards passing and 62 yards rushing, but their opponent had 165 yards in defensive penalties.

When you count all of their yards and all of the penalty yards, how many yards did the Raiders gain?

The following page(s) contains the answers to the tasks in the lesson activity.

Try some.

- 5 x (-4) = 20

- 5 x 4 = -20

6 x (-7) = -42

- +

+

+

-

- -

- -

Try some.

-48 ÷ 6= -8

24 ÷ -6= -4

-63 ÷ -9= 7

- + -

+ - -

- - +

Try some on your own.

6 + (-8) = -2

2 + (-7) = -5

-4 + 6 = 2

-9 + 3 = -6

-5 + 2 = -3

The Washington Redskins gained 256 rushing yards in a game. They also lost 4 yards on one play. The quarterback threw for 154 yards, but he was sacked seven times. He lost a total of 53 yards on the sacks. How many total yards did the Redskins gain?

353 total yards

In one game the San Diego Chargers gained 187 yards rushing and 458 passing. But they had 211 yards of penalties against the offense.

How many total yards did they gain that night?

434 total yards

The New England Patriots are a passing team. They ran for only 47 yards last night, but they passed for 398. They lost 38 yards on sacks, and they had three offensive penalties against them for a total of 25 yards.

How many total yards did they gain last night?

382 total yards

The Oakland Raiders only gained 75 yards passing and 62 yards rushing, but their opponent had 165 yards in defensive penalties.

When you count all of their yards and all of the penalty yards, how many yards did the Raiders gain?

302 total yards

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