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When the signs are different, subtract
the numbers and the answer is the sign
of the bigger number
15  5   10
When the signs are the same, add the
numbers and the answer is the same
sign.
 8  10   18
Add the opposite!!!
 3 7
Signs are
the same, so
we add
 3 7
Step 1: Draw 3 negatives
Step 2: We don’t have any
positives to take away, so we
add 7 positives and their
opposites.
Step 3: Take away 7
positives.
Answer: 10 negatives are left
Add the opposite!!!
8  (4)
Signs are
the same, so
we add
8  (4)
Step 1: Draw 8 positives
Step 2: We can’t take away 4
negatives, so we add 4
negatives and their opposites.
Step 3: Take away 4 negatives.
Answer: 12 positives are left
Add the opposite!!!
5 8
Signs are
different,
so we
subtract
5 8
Step 1: Draw 5 positives
Step 2: We can only take away
5 positives so we add 3 more
positives and the opposite, 3
negatives
Step 2: Now take away 8
positives.
Answer: 3 negatives are left
Add the opposite!!!
 8  2
Signs are
different,
so we
subtract
 8  2
Step 1: Draw 8 negatives
Step 2: Take away 2 negatives
Answer: 6 negatives are left
Add the opposite!!!
 3  (10)
Signs are
different, so we
subtract
Add the opposite!!!
10 14
Signs are different,
so we subtract
Add the opposite!!!
10  9
Signs are the
same, so we add
Don’t forget to add the opposite!!!
1.
2.
3.
4.
5.
6.
-8 - 14 1. Becomes –8 + -14 = -22
14 - 25 2. Becomes 14 + -25 = -11
-6 - 4 3. Becomes –6 + -4 = -10
-12 - -184. Becomes –12 + 18 = 6
-22 - -4 5. Becomes –22 + 4= -18
9 - -12 6. Becomes 9 + 12 = 21
1) The entrance to a mine is 2,457 feet above sea
level. The bottom of the mine is 5,642 feet
below the entrance. What is the elevation of
the bottom of the mine?
A. -8,099 ft
B. -3,185 ft
C. 3,185 ft
D. 8,099 ft
2) During the first seven plays of a football game,
the team made the following yardage: +3, -8,
+14, -4, +25, +7, and -10. What was the net
yardage?
F. -49 yd
G. -22 yd
H. 27 yd
J. 49 yd
3) Which of the following expressions does NOT
have the same value as the others?
A.
-30 – (-30)
B.
-72 + 12
C.
D.
-14 + (-46)
-28 - 32
4) In 2000 a company’s sales were $52 million. In
2001, the sales changed by -$7 million. In
2002, the sales changed by +$3 million. What
were the company’s sales in 2002?
F.
$42 million
G.
$48 million
H.
$56 million
J.
$62 million
5) The highest temperature ever recorded in the
world is 136°F. The lowest temperature ever
recorded in the world is -129°F. What is the
difference between the highest recorded
temperature and the lowest recorded
temperature?
A.
-265°F
B.
-7°F
C.
7°F
D.
265°F
6) Several classmates were playing a game using a
number line, moving a game piece to the right
for positive numbers and to the left for
negative numbers. Mel began at zero. After
Mel made moves of +7, -12, and -1, what move
did he need to make to end on zero?
F.
-6
G.
-4
H.
+4
J.
+6
-12-11-10 -9 -8 -7 -6 -5 -4 -3 -2 -1 0 1 2 3 4 5 6 7 8 9 10 11 12