Chapter 2 Lesson 5Dividing Integers

pgs. 80-84

What you’ll learn:Divide Integers

Find the average of a set of data

Vocabulary

Mean (82)--the average of a set of data

This is not related to how you treat your sibling(s)!!

Key Concepts (80, 81):

Dividing Integers with the SAME sign:

The quotient of two integers with the same sign ispositive.

-12 =4 12 =4 -3 3

Dividing integers with Different signs:

The quotient of two integers with different signs isnegative.

-12 = -3 12 = -3 4 -4

Divide these integers with the same sign:a. -32/(-8)

b. 75 5

c. -18(-9)

d. 60/10

Concept check: How do you know the sign of thequotient of two integers?

4

15

2

6

Divide these integers with different signs:

a. 42 -3

b. -48 6

c. -306

d. 40/(-8)

-14

-8

-5

-5

Remember, if the signs are different,Then the quotient is NEGATIVE

Evaluating Algebraic Expressions:

Evaluate ab if a = -6 and b = -8 -4

Replace the a with -6 and the b with -8.

(-6)(-8) -4

Multiply (-6)(-8) which equals 48.

Now the problems looks like this:

48 Which equals -12 -4

Mean:To find the mean of a set of numbers, find the sum ofThe numbers and then divide by the number in the set.

Rachel had test scores of 84, 90, 89 and 93. Find theAverage (mean) of her test scores.

First, find the sum of the test scores and divide by the Total number of test scores.

84+90+89+93---test scores4 ---total number of tests

356 --sum of test scores =89 4 --number of tests The average of her test

scores is 89.

Extra Practice:Evaluate each expression if a=

-2, b = 5 and c = -4

a. ac -8

b. 250 ab

Find the mean of the data:

c. 23, 20, 27, 18

d. -8, 9, 4, 0, 2, -1

-1

-25

22

1

HOMEWORK:

QUIZ TOMORROW OVERSECTIONS 2-4 AND 2-5!!

STUDY OR ELSE(you might earn a bad grade)