Download Adding and Subtracting Integers Brain-Pop

Bellwork
Have your homework out on your desk!
Warm Up
Compare. Use <, >, or =
1.
7
2. -32
-5 >
65 <
3. 82
-28 >
4. 64
48 >
2-2
Adding
Adding
Integers
3
Integers
Ways!
Pg. 82
Essential Question
How do you add
positive and negative
numbers?
3 Ways to ADD Integers
1. Integer Chips
2. Rule/Song
3. Number Line
4
Adding and Subtracting
Integers Brain-Pop
http://www.brainpop.com/math/numbersandoperations/addingandsubtractin
gintegers
 Write down 2 facts
from the clip…
 1.
 2.
Integer Chips
 Each chip has a yellow side and
a red side.
 Yellow is POSITIVE
 Red is NEGATIVE
6
Practice with Chips
 Represent
 A. 4
 B. -8
 C. -3
 D. 2
 E. 0
7
In the Black or in the Red?
 When business records were kept by
hand, accountants used red ink for
expenses and black
ink for
income. If your income was greater
than your expenses, you were “in
the black.” If your expenses were
greater than your income you were
“in the red.”
8

In the Black or in the Red?
 Solve this problem:
 Linda owes her sister $6 since she
helped her babysit. She earns $4
delivering papers with her brother.
Is Linda “in the red” or “in the
black?”
9
Using Integer Chips
 The first way to add integers is
to use integer chips.
10
Opposites Cancel
 When we first introduced INTEGERS
we learned that every integer has an
OPPOSITE.
 When you combine OPPOSITES, they
equal 0. They cancel. (Represent the
following equations using integer
chips.)
 A. 4 + -4 = 0
 B. -2 + 2 = 0
11
Steps:
- Use chips to represent the
first number.
- Use chips to represent the
second number.
Remember:Yellow-Positive
& Red-Negative
12
MORE Steps:
Cancel out any zeropairs.
Whats left?
How many?
What color?
13
Example 1
Find each sum.
–4 + 8
The signs are different so were finding the difference.
–4 + 8
Think: 8 – 4 = 4.
4
Examples 2&3
12 + 1 = 13
The signs are the same so I put a negative in front.
= -13
= 11
NOW: Gather 5 yellow chips and 9 red chips. Find
the total value for each set of chips. Always use 5, -9 as
your starting point.
a. original set of chips = ____
b. add 3 yellow chips = ____
c. remove 3 red chips = ____
d. remove 2 yellow chips = ______
e. add 2 red chips = ______
16
TRY THESE:
 A.
 B.
 C.
 D.
 E.
-4 + 5 =
3+4=
5 + -2 =
3 + (-6) =
-4 + -2 =
17
Getting Harder...
 7 + _____ = 1
 ____ + - 5 = -2
 -3 + _____ = -6
18
Even harder...
 What are two combinations of
chips that would equal...
0
4
 -3
19
What if I don’t have chips?
You can DRAW integer
chips.
Example:
-4 + 7
20
Integer Lab- Sums
Positive Plus Positive
4 + 2
3 + 3
1 + 6
21
Integer Lab- Sums
Negative Plus Negative
 -3 + -2
 -1 + -1
 -6 + -5
22
Integer Lab- Sums
+ Plus -/- Plus +
 4 + -2
 2 + -7
 -5 + 1
 -3 + 6
23
Integer Lab - Sums
 1. The sum of two positive
integers is
___________________
because
_________________________
_________________________
________.
24
Integer Lab - Sums
 1. The sum of two positive
integers is POSITIVE because
both numbers are positive.
25
Integer Lab - Sums
 2. The sum of two negative
integers is
___________________
because__________________
_________________________
_______________.
26
Integer Lab - Sums
 2. The sum of two negative
integers is NEGATIVE because
both numbers are negative.
27
Integer Lab - Sums
 3. The sum of a positive
number and a negative number
_________________________
_________________________
_________________________
_________________________
_________________________
28
Integer Lab - Sums
 3. The sum of a positive
number and a negative number
varies. You will subtract the
numbers and take the largerlooking number’s sign.
29
Integer Addition Rules
 Rule #1 – If the signs are the
SAME, pretend the signs aren’t
there. Add the numbers and then
put the sign of the addends in
front of your answer.
9 + 5 = 14
-9 + -5 = -14
Integer Addition Rules
 Rule #2 – If the signs are
DIFFERENT pretend the signs
aren’t there. Subtract the smaller
from the larger one and put the
sign of the one with the larger
absolute value in front of your
answer.
Larger
-9 + +5 =
9 - 5 = 4 Answer = - 4
Integer Addition Song
 To the tune of Row-Row-Row-Your-Boat...
 Same signs ADD and Keep!
 Different signs SUBRTACT,
take the sign of the higher
number, then you’ll be exact.
32
3 Ways to ADD Integers
1. Integer Chips
2. Rule/Song
3. Number Line
33
Solving Using a Number Line
1. Start at zero
2. Move either left or right the number
of spaces from zero
3. From where you landed move the
number of spaces left or right that
the second number indicates
4. Where you land is the answer to the
equation
Example 4
Use a number line to find each sum.
–7 + 12
12
–7
–12
–10
–8
–6
–4
–2
0
–7 + 12 = 5
2
4
6
8
Example 5
Use a number line to find each sum.
–7 + (–4)
–14
–12
–7
+(–4)
–10
–8
–6
–4
–7 + (–4) = –11
–2
0
2
Example 6 and 7
-4 + -2
–12
–10
–8
–6
–4
–2
0
2
4
6
8
-3 + 5
–12
–10
–8
–6
–4
–2
0
2
4
6
8
Practice
Page 84
(2-10) even
Work Session
Page 84
(14-28; 34-44)
GRADED
Homework
 Workbook pg. 14
 All problems