1. Grade 6-Adv : Operations with Rational Numbers
Addition & Subtraction with Positive and Negative Fractions and Decimals
Key Vocabulary:
Absolute Value
Opposites
Additive Inverse

2. OBJECTIVE:
Be able to determine the sum or difference of two or more rational numbers using the rules of addition and subtraction. Then justify the solution by constructing and reasoning about a number line.

3. -25 + (-14) 78 + (-13) 45 – (-37) 23 - 149 WARM UP
Instruction: Simplify the expressions
-25 + (-14)
78 + (-13)
45 – (-37)

4. REVIEW
Rules for Adding & Subtracting Integers
Addition:
Same Signs Add the absolute values & give the sum the sign of the original numbers.
Different Find the difference of the
Signs absolute values & use the sign of the number with the
larger absolute value.
Subtraction: Add the Opposite & refer to rules for addition.
Keep 1st term,
Change operation to addition and,
Change 2nd term to its opposite.

5. EXPLORE Apply the Rules to Fractions and Decimals
Example 1: ½ ¾
Example 2: 5 ½ - (-2 ½)
Example 3: (-25)
Example 4: (-55.9)

6. Explain: Solution: - 4 ¼ Apply the Rules to Fractions and Decimals
Example 1: Same signs, so add absolute values
- 3 ½ ¾
Solution: - 4 ¼

7. Explain: 5 ½ - (-2 ½) Solution: 8
Apply the Rules to Fractions and Decimals
Example 2: Rewrite as addition: 5 ½ + (+ 2 ½ )
5 ½ - (-2 ½)
Solution: 8

8. Explain: Solution: -8.2 Apply the Rules to Fractions and Decimals
Example 3: Different Signs, so find the difference
of absolute values & make answer (-)
(-25)
Solution: -8.2

9. Explain: Solution: 12.1 Apply the Rules to Fractions and Decimals
Example 4: Rewrite as addition: (+55.9)
& follow rules for addition. Different signs, so find the difference of absolute values.
-43.8 – (- 55.9)
Solution:

10. PRACTICE Concept Check before Independent Practice 1) 6 ¼ - (-3 ½ )
1) 6 ¼ - (-3 ½ ) 2)
Instructions: Complete the following items on practice worksheet. (Homework – finish classwork)
Fractions Worksheet #9 - #14
Decimals Worksheet # 1- #13 odd only

11. Solutions to Practice Fractions Worksheet: Decimals Worksheet:
9) / ) ) 1/ ) / ) 7/ ) 3/8
Decimals Worksheet:
1) ) ) ) ) ) ) -6.5