.

1. Dividing Integers
• LEARNING TARGET
– I can divide positive and negative numbers.
• FOCUS QUESTION
– How are the rules for multiplying integers and
dividing integers connected? Why?

2. Dividing Integers
I can divide positive and negative
numbers.

3. Division Rules
• a POSITIVE divided by POSITIVE is POSITIVE
(+) ÷ (+) = (+)
• a NEGATIVE divided by NEGATIVE is POSITIVE
(-) ÷ (-) = (+)
• a POSITIVE divided by NEGATIVE is NEGATIVE
(+) ÷ (-) = (-)
• a NEGATIVE divided by POSITIVE is NEGATIVE
(-) ÷ (+) = (-)

4. EXAMPLE 1
=
a. – 40
–8
b. –14
2
c. 36
–9 =
d. 0 =
–7
Dividing Integers
=

5. EXAMPLE 1
Dividing Integers
Same sign, so quotient is positive.
= –7 Different signs, so quotient is negative.
a. – 40
–8
b. –14
2
c. 36
–9 = –4 Different signs, so quotient is negative.
d. 0 = 0
–7
Dividend is 0 so quotient is 0.
= 5

6. Dividing with Zero
0 ÷ -7 = 0
-7 0
Dividing nothing into
7 groups means
everyone gets
nothing.
-10 ÷ 0 = undefined
0 -10
There is no way to
put -10 into zero
groups so it is
undefined.

7. GUIDED PRACTICE for Examples 2 and 3
Find the mean of the data.
1. –16, 17, 8, –23, –31

8. GUIDED PRACTICE for Examples 2 and 3
Find the mean of the data.
1. –16, 17, 8, –23, –31
SOLUTION
STEP 1 Find the sum of the values.
–16 + 17 + 8 + (–23) + (–31 )
= –45
STEP 2 Divide the sum by the number of values.
–45
5
= –9
ANSWER The mean of the data is about –9.

9. Order of Operations
A set of rules to simplify a numerical
expression.
1.Evaluate expressions inside grouping
symbols (brackets and parenthesis)
2.Multiply and divide from left to right
3.Add and subtract from left to right

10. EXAMPLE 3
Evaluating Expressions
Evaluate the expression when a = –24, b = 8, and
c = –4.
a. a
b
b. ab
c

11. EXAMPLE 3
Evaluating Expressions
Evaluate the expression when a = –24, b = 8, and
c = –4.
b = –24
a. a
8
b. ab
c
= –24 8
–4
= –192
–4

12. EXAMPLE 3
Evaluating Expressions
Evaluate the expression when a = –24, b = 8, and
c = –4.
b = –24
a. a
8
Substitute values.
Different signs, so quotient is negative.
b. ab
c
Substitute values.
= –3
= –24 8
–4
= –192 Multiply.
–4
= 48 Same sign, so quotient is positive.

13. Daily Homework Quiz For use after Lesson 2.5
Find the quotient.
Evaluate the expression when k = – 36, m = 6, and n = 3.
1. mn
k 3. m2 + 4n2
k 2. m + n
2k

14. Daily Homework Quiz For use after Lesson 2.5
Find the quotient.
Evaluate the expression when k = – 36, m = 6, and n = 3.
1. mn
k
ANSWERS 1
– 2
k 3. m2 + 4n2
2. m + n
2k
ANSWERS – 4 ANSWERS – 1

15. Quick Write
How are the rules for multiplying integers
and dividing integers connected? Why?

16. Practice:
• Perform the indicated operation.
1. 21 ÷ -7 =
2. 35 ÷ 5 =
3. 64 ÷ -16 =
4. -88 ÷ 11 =
5. I -81 I ÷ I 9 I =
6. -10 ÷ 0 =

17. Practice:
• Perform the indicated operation.
1. 21 ÷ -7 =
2. 35 ÷ 5 =
3. 64 ÷ -16 =
-8
-3
4. -88 ÷ 11 =
5. I -81 I ÷ I 9 I =
6. -10 ÷ 0 =
7 9
-4
Undefined