Transcript Section 5.2 “Adding and Subtracting Like Fractions”

Do Now 3/7/11

Copy HW in your planner.
 Text p. 228, #10-28 evens, 38-44 evens
 Quiz sections 5.2 & 5.3 Wednesday

Be ready to copy POTW #7.

Be ready to finish quiz on section 5.1 from Friday.
Objective

SWBAT add and subtract like fractions.
Section 5.2 “Adding and Subtracting Like Fractions”
Adding Fractions with Common Denominators
To ADD fractions with common denominators, add
their numerators together. Simplify if necessary.
Add the numerators
a b ab
 
c c
c
2 3

7 7
2 3 5
 
7 7 7
Section 5.2 “Adding and Subtracting Like Fractions”
Subtracting Fractions with Common
Denominators
To SUBTRACT fractions with common
denominators, subtract their numerators. Simplify if
necessary.
Subtract the numerators
a b a b
 
c c
c
5 1

6 6
4 2
 
6 3
Try It Out!!
Solve
5 2

8 8
5 2 7
 
8 8 8
6  5
  
18  18 
6 5 1


18 18 18
5 2

12 12
5 2
3 1
 

12 12 12 4
3 2
 
5 5
3 2
5
     1
5 5
5
Mixed Numbers to Improper Fraction
1 41
8 
5 5
40 + 1 = 41
8 x 5 = 40
Try it out…
Mixed Numbers to Improper Fraction
15 + 2 = 17
3 x 5 = 15
2 17
3 
5 5
42 + 5 = 47
7 x 6 = 42
5
47
7  
6
6
-
“Adding and Subtracting Mixed Numbers”
Adding & Subtracting Mixed Numbers
To ADD & SUBTRACT mixed numbers do the
following:
1. Write the fractions as improper fractions
2. Add or subtract the numerators
3. Simplify if necessary
4
3
3 4
6
6
22 27

6
6
49

6
49
1
8
6
6
Find the sum or difference.
5
7
5 2
9
9
Make fractions improper
50 25


9
9
Add fractions
75

9
Write as mixed number
1
8
3
Find the sum or difference.
7
3
4 2
8
8
Don’t forget your
integer rules.
-39 + 19 = -20
Make fractions improper
 39 19


8
8
Add fractions
 20

8
Write as mixed number
4
1
 2  2
8
2
Find the sum or difference.
3
1
 10  6
7
7
Make fractions improper
 73 43


7
7
Don’t forget your integer
rules. “Opp-Opp”
-73 + (-43) = -116
Add fractions
 73  (43)  116


7
7
Write as
mixed
number
4
 16
7
NJASK7 Prep
Homework
 Text
p. 228, #10-28 evens, 38-44 evens