1-4 adding integers course 3 warm up warm up problem of the day problem of the day lesson...
TRANSCRIPT
1-4 Adding Integers
Course 3
Warm Up
Problem of the Day
Lesson Presentation
Warm UpGraph each number on a number line.
1. –5 2. 7
3. –4 4. 0
Course 3
1-4 Adding Integers
–5 –4 –3 –2 –1 0 1 2 3 4 5 6 7
Problem of the Day
Start at (0, 0). Walk 3 blocks west and 2 blocks north. Then walk 4 blocks south and 1 block east. What are your coordinates?
Course 3
1-4 Adding Integers
(–2, –2)
Learn to add integers.
Course 3
1-4 Adding Integers
Course 3
1-4 Adding Integers
To add a positive number move to the right. To add a negative number move to the left.
Helpful Hint
Additional Example 1A: Using a Number Line to Add Integers
Use a number line to find the sum.
(–6) + 2
2
–6
You finish at –4, so (–6) + 2 = –4.
–6 –5 –4 –3 –2 –1 0 1 2 3 4 5
Course 3
1-4 Adding IntegersAdditional Example 1B: Using a Number Line to Add
IntegersUse a number line to find the sum.
–3 + (–6)
-3
–6
You finish at –9, so –3 + (–6) = –9.
–9 –8 –7 –6 –5 –4 –3 –2 –1 0 1 2
Course 3
1-4 Adding Integers
Check It Out: Example 1A
Use a number line to find the sum.
(–3) + 7
7
–3
You finish at 4, so (–3) + 7 = 4.
–6 –5 –4 –3 –2 –1 0 1 2 3 4 5
Course 3
1-4 Adding Integers
Check It Out: Example 1B
Use a number line to find the sum.
(–2) + 4
4
–2
You finish at 2, so (–2) + 4 = 2.
–6 –5 –4 –3 –2 –1 0 1 2 3 4 5
Course 3
2-1 Adding Integers
Additional Example 2: Using Absolute Value to Add Integers
A. 1 + (–2)
Add.
1 + (–2)
2 > 1; use the sign of 2. –1
B. (–8) + 5
(–8) + 5
8 > 5; use the sign of 8. –3
Think: Find the difference of 1 and –2 .
Think: Find the difference of –8 and 5 .
Course 3
1-4 Adding Integers
Additional Example 2: Using Absolute Value to Add Integers
C. (–2) + (–4)
Add.
(–2) + (–4)
Same sign; use the sign of the integers. –6
Think: Find the sum of –2 and –4 .
Course 3
1-4 Adding Integers
Check It Out: Example 2
A. 3 + (–6)
Add.
3 + (–6)
6 > 3; use the sign of 6. –3
B. (–4) + 1
(–4) + 1
4 > 1; use the sign of 4. –3
Think: Find the difference of 3 and –6 .
Think: Find the difference of –4 and 1 .
Course 3
1-4 Adding Integers
Check It Out: Example 2C
C. (–6) + (–7)
Add.
(–6) + (–7)
Same sign; use the sign of the integers. –13
Think: Find the sum of –6 and –7 .
Course 3
1-4 Adding Integers
Additional Example 3: Evaluating Expressions with Integers
Evaluate c + 4 for c = –8.
c + 4
Replace c with –8.
8 > 4; use the sign of 8.
(–8) + 4
–8 + 4 = –4
Think: Find the difference of –8 and 4 .
Course 3
1-4 Adding Integers
Check It Out: Example 3
Evaluate d + 7 for d = –3.
d + 7
Replace d with –3.
7 > 3; use the sign of 7.
(–3) + 7
–3 + 7 = 4
Think: Find the difference of –3 and 7 .
Course 3
1-4 Adding Integers
Additional Example 4: ApplicationMeka opened a new bank account. Find her account balance after the first four transactions listed below.
Deposits: $200, $20 Withdrawals: $166, $38
Use a positive sign for deposits and a negative sign for withdrawals.
200 + 20 + (–166) + (–38)
Group integers with same signs.(200 + 20) + (–166 + –38)
Add integers within each group.220 + (–204)
220 > 204; use the sign of 220.16
Meka’s account balance after the first four transactions is $16.
Course 3
1-4 Adding Integers
Check It Out: Example 4Michael opened a new bank account. Find his account balance after the first four transactions listed below.
Deposits: $175, $95 Withdrawals: $133, $65
Use a positive sign for deposits and a negative sign for withdrawals.
175 + 95 + (–133) + (–65)
Group integers with same signs.(175 + 95) + (–133 + –65)
Add integers within each group.270 + (–198)
270 > 198; use the sign of 270.72
Michael’s account balance after the first four transactions is $72.
Lesson Quiz: Part I
Add.
1. –7 + (– 7)
2. 15 + (–9) + (–2)
4
–14
Insert Lesson Title Here
Course 3
1-4 Adding Integers
Evaluate each expression for the given
value of the variable.
3. 13 + r for r = –15
4. 2 + b + (–9) for b = –6
–2
–13
Lesson Quiz: Part II
5. On Monday, a local dog shelter had six dogs.
By Friday they had found homes for three, but
took in two more. Then how many dogs were in
the shelter?
Insert Lesson Title Here
Course 3
1-4 Adding Integers
5 dogs