#### Transcript of Lesson 2.1 Multiplying Integers

**Lesson 2.1 Multiplying Integers**

Essential Question:

How do you multiply integers?

Using a Number Line

One way to multiply integers is to use a number line. For example if youhad to problem 3(-2), you would start at the zero on the number line and move to left six spaces, giving you the answer of -6.

Multiplying More Than Two Numbers

When multiplying more than one number, you must remember the chart shown in the first slide. If you had the problem -2(-3)(2), you would work from left to right. -2 times -3 equals 6, according to the chart, and 6 times 2 would equal 12.

Multiplying A Fraction By A Fraction

To multiply a fraction and a fraction together, is very simple. If your problem is 4 over 10 times 3 over 10, you just multiply each number that is across, so with this example you would get 12 over 100, but DON'T FORGET TO SIMPLIFY!!! So your answer would actually be 3 over 25. If your problem has different denominators then it is just like adding and subtracting fractions, find a common denominator and then multiply. It's that easy!

Multiplying A Fraction and A Decimal

When multiplying a fraction and a decimal remember to make the decimal a fraction by taking the number behind the decimal and seeing which spot it is (.9= 9\10 because nine is in the tenths place). Then all you need to do is multiply the fractions as normal and

DON'T FORGET TO SIMPLIFY!!!!!

When multiplying positive numbers together, it is basically lie plain old regular multiplication, BUT with either both negatives or a positive and a negative integer, there are rules to solve these kinds of problems. The chart below shows how to solve each kind of problem.

+ x + = +

+ x - = -

- x + = -

- x - = +

On Your Own...

Multiply each number

1. -4(12) 2. -6 x 7(-8) 3. 4.25(-9.5) x 3 4. 2\3 x .62 5. 8\10 x 2\6

Solve Using a Number Line

6. -2(9) 7. -3(-5)

8. Tina's account had two hundred dollars as of this morning. Tina wrote six checks for thirty-two dollars each. She went to the grocery store and purchased two pounds of apples for three dollars a pound and three gallons of milk for three dollars and fifty cents. Tina then made a deposit of fifty dollars. What is her current balance?

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