Get ready before the bell rings!Take out homework and a pencil to

prepare for the homework quiz!Send one person to get textbooks for

your table.Check the file folder for your class to

pick up graded workLocated by the bookshelf, blue crate.Look behind the tab for your class

period and take home anything with your name on it.

Chapter 2: Accentuate the Negative

Investigation 3: Multiplying & Dividing Rational Numbers

Launch

A note on notation: Multiplication Symbols

Check your answer: 106.2 seconds

3.1 Multiplication Patterns with IntegersFocus Questions: How is multiplication

of two integers represented on a number line and chip board?

Number Relay Race

3.1 Number Relay Race

•How far does each runner race?•Explain what the first leg of the race looks like.•Explain the last leg of the race.

Turn to Page 56 in your Textbook

Problem 3.1 – A – 1 - aWhat does 5 meters per second mean?Which way is Hahn running? Left or right? Positive

or Negative?What number sentence could you write to show

where Hahn will be in 6 seconds if he is going to the right and passes the 0 point running 5 meters per second?

Suppose Hahn was running 5 meters per second to the left. How would this change the number sentence?

What would the number sentence look like now?What do the -5, the 6, and the -30 indicate in this

situation?Finish question A with your table.

Problem 3.1 - B

Now complete C & D with your tablemates.

Problem 3.1 - E

Check for UnderstandingPredict the sign of the product for

each calculation and then show the calculation on a number line.

2 x (-3)-2 x (-3)-2 x 32 x 3

Problem 3.2 Multiplication of Rational Numbers

Focus Question: What algorithm can you use for multiplying integers?

Turn to page 58 in your textbook.

Problem 3.2

Check your answers:1. (+ rational number) x (+ rational number) = + 2. (+ rational number) x ( - rational number) = -3. (- rational number) x (- rational number) = +

Problem 3.2

3.3 Division of Rational Numbers

Focus Question: What algorithm can you use for dividing integers? How are multiplication and division of integers related?

Launch36 ÷ 4 = 9

What does this number sentence mean?

How are the operations of multiplication & division related?

What number sentence would undo: 3 • 12 = 36?

Fact Families

Turn to Page 61 and complete A & B for Problem 3.3

Review of Rational Numbers

Complete Problem C on Page 61

Division is not commutative, the order matters.

If you add zero to any number, you get that same number.

Yes, it is 1.

When you add together opposites, you get zero,.

Yes, it is called the reciprocal.

For example: 2 x ½ = 12 and ½ are multiplicative inverses.

Review Vocabulary1) Multiplicative identity: one times any

number is the same number.

2) Multiplicative inverse: any rational number multiplied by it’s reciprocal is 1

3) Reciprocal: inverting a fraction (upside down)

4) Terminating vs. repeating decimal: terminating decimals end; repeating decimals continue forever with a pattern.