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2.2
Subtracting Rational Numbers
2.2 – Subtracting Rational #s
 Goals / “I can…”


Subtract rational numbers
Apply subtraction
2.2 – Subtracting Rational #s
Example: Using a number line
 Yesterday when we added, we moved the
line to the right. Today when we subtract
we move it to the left.
2.2 – Subtracting Rational #s
Using your calculator, do the following
problems:
5 + (-7) =
5–7=
-6 + (-3) =
-6 – 3 =
 What conclusion can you make?
2.2 – Subtracting Rational #s
 RULE: Add the opposite - to subtract a
number, switch the subtraction sign to
add and take the opposite of the next
number
2.2 – Subtracting Rational #s
Example:
-6 – 7 =
2.5 – (-7.6) =
2.2 – Subtracting Rational #s
 How did we solve  8  ?
2.2 – Subtracting Rational #s
 What if we had more than one number in
the absolute value?
 Treat them like parentheses.
2.2 – Subtracting Rational #s
 Example: Simplify
12  6
19  27
 14  (16)
2.2 – Subtracting Rational #s
Example: Evaluating Expressions
 Let x = -3 and y = -6
1. x – y
2. y – x
3. –x – y
4. –x – (-y)