Transcript 6.3 Adding and Subtracting Mixed Numbers

Team Travel
• The 57 players on four soccer teams traveled to a soccer
tournament in Plainville. Each car carrying the members
of the same team had the same number of players in it.
• The 15 players on the Barracudas rode three to a car.
• The Sharks and the Dolphins had three fewer players on
each team than the Barracudas had.
• The Sharks had one more player in each car than the
Dolphins had.
• The Stingrays had six players per car.
• In all, how many cars did the soccer players take to
the tournament?
Answer
•
•
•
•
•
Barracudas15 players ÷ 3 = 5 cars
Sharks12 players ÷ 4 = 3 cars
Dolphins12 players ÷ 3 = 4 cars
Stingrays18 players ÷ 6 = 3 cars
Add the number of cars for each team to
find out the total number of cars the teams
took to the soccer tournament.
5 + 3 + 4 + 3 = 15; 15 cars in all
Adding and Subtracting Mixed
Numbers
Lesson 6-3
Review - Adding and Subtracting
Fractions with Like Denominators
• To add or subtract fractions with like
denominators, add or subtract the
numerators and write the result over the
denominator. Simplify the fraction.
1
5
+
3
5
=
4
5
The denominator
always stays the same.
Review - Adding and Subtracting
Fractions with Unlike Denominators
• Find the LCD, rename the fractions. Then
add or subtract with like denominators.
7
5
8
6
21
20
24
24
2
8
6
4 3
2 x 4 x 3 = 24 LCD
1
=
24
7
21
5
20
8
24
6
24
Adding and Subtracting Mixed
Numbers
• First add or subtract the fractions. If
necessary, rename the fractions with the
LCD. Then add or subtract the whole
numbers and simplify.
4
7
9
2
+ 10
9
= 17
6
9
= 17
2
3
Try Some More
5
8
6
5
8
_
6
_
1
2
3
3
=
6
3
2
2
2
6
1
3
=
6
6
LCD = 6
1
=
6
2
Try Some More
5
1
9
10
1
18
+ 4
+ 4
1
6
3
=
3
3
18
9
13
=
5
18
6
2
LCD = 18
Your Turn
1
3
12
7
9
10
+ 14
-
7
12
2
= 17
3
4
5
3
1
=
5
10
Another Example
5
11
9
5
11
9
5
11
-
9
-
2
8
3
6
8
10
9
14
9
3
9
3
3
1
LCD = 9
Borrow from the whole number,
to get a larger numerator.
One whole is equal to 9 pieces.
Add 9 + 5 to get the new
numerator.
Another Example
2
14 10
8
3
9
= 2
8
9
Another way to look at it…
1
3
4
3
wholes
Another way to look at it…
1
3
4
5
pieces
2
wholes
1
3
4
Can be
renamed as…
5
2
4
Another Example
3
2
8
8
+ 5
1
10
8
2
7
8
10
=
2
1
8
7
8
Rename the
improper fraction.
2
+ 7 =
8
8
1
=
8
4
Practice / Homework
• Practice: Text pg. 250 # 15-22
• Homework: Lesson 6-3 # 2-24 evens
• Quiz Friday: Lessons 6-1, 6-2, 6-3
(Estimating fractions, adding and
subtracting fractions and mixed numbers)