Download CHAPTER 1: REAL NUMBERS Section 1.7: Subtraction of Real Numbers Topics: A.

MATH 0960
Section 1.7 Notes
CHAPTER 1: REAL NUMBERS
Section 1.7: Subtraction of Real Numbers
Topics:
A. Subtract numbers.
B. Evaluate expressions containing more than two numbers.
C. Solve application problems.
A. Subtract numbers.
 What does a problem look like?
Examples: Subtract.
1)
Answer:
2)
Answer:
3)
(
)
Answer:

What am I supposed to do?
o There is a distinct difference between addition and subtraction. In
addition the order of the numbers does not matter. We say two addends
are added to find their sum. In subtraction, on the other hand, the
subtrahend is subtracted from the minuend to find their difference.
Because of this the rules for adding do not apply to subtraction.
o Subtraction problems can be changed into addition problems by adding
the opposite of the second number (subtrahend) to the first number
(minuend).

What do I need to know?
o Changing subtraction to addition can be a helpful way to practice
subtraction but is not practical in the long run. Why use two symbols
when one will do?
o Adding a negative and subtracting a positive are both just forms of
subtraction.
o Subtracting a negative becomes addition. We call this “cancelling the
double-negative.”
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MATH 0960
Section 1.7 Notes
B. Evaluate expressions containing more than two numbers.
 What does a problem look like?
Example: Evaluate.

Answer:
What do I need to know?
o Once you have cancelled all double-negatives in a problem just remember
to observe the sign in front of each number.
o Remember the sum of opposites equals zero.
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