1. Subtracting Rational Numbers Unit 2 Lesson 3
Learning Objective:
Students will be able to
Subtract Rational Numbers-Fractions and Decimals

2. SUBTRACTING Rational Numbers
UNIT 2-Lesson 3
Subtraction is the same as adding the opposite.
To subtract rational numbers, use the same rules for signs we used for integers.
Turn the problem into an addition problem and solve.
Brainpop video- adding and subtracting integers

3. Subtracting Rational Numbers
Example:

4. Subtracting Rational Numbers
Example:
1) Find 12.8 – 21.6 =_____ What should I do?
12.8 +(-21.6) = - 8.8
2) Find – (-20.5) = ??

5. Let’s try some together:
Subtracting Rational Numbers
Let’s try some together:

6. Subtracting Like Denominators
Adding and Subtracting Fractions with like Denominators
Subtracting Like Denominators
Key Concept Subtracting Like Fractions
Words: To subtract fractions with like denominators, subtract the numerators and write the difference over the denominator.
Symbols: a ­ b a – b ,where c 0
c c c
Example: ≠ = = or
Example 3 2 - = 5 5

7. Adding Rational Numbers
Quick Review of
Adding Rational Numbers
Find =
Find (-3 ) =

8. Subtracting Rational Numbers
Finding Distances Between Numbers on a Number Line
* Distance between two numbers on a number line is the Absolute Value of the difference of the numbers.

9. You Try Subtracting Rational Numbers
Finding Distances Between Numbers on a Number Line
You Try

10. Convert the subtraction problem into an addition problem. 8.2 – 4.4 B
8.2 + (-4.4) C
(-4.4) D
Answer: B

11. Convert the subtraction problem into an addition problem.
(-10.1) A B
3.7 + (-10.1) C
(-10.1) D
Answer: A

12. Convert the subtraction problem into an addition problem.
Answer: C C D

13. Convert the subtraction problem into an addition problem.
Answer: D

14. Convert the subtraction problem into an addition problem.
1 - 9 A
-1 + 9 B
1 + (-9) C
-1 + (-9) D
1 + 9
Answer: B

15. Activities
Journals Page Activities #1 & #2 -Work with a partner Homework: Journal pg. 36 ALL