Transcript Slide 1

Subtracting Mixed Numbers
Subtracting Mixed Numbers
Convert Mixed Numbers to Improper fractions
Find the Least Common Denominator
Make Equivalent fractions
Subtract numerators keep same denominators
Change improper fraction to mixed number, If necessary
Reduce fractions, if necessary
Problem # 1
First: Convert Mixed Numbers
to Improper fractions
10
3
1
2
2
3
Is this where I
multiply the
numerator and the
whole number?
No!
Gotcha!
Problem # 1
First: Convert Mixed Numbers
to Improper fractions
Let me try again!
Is this where I add
the numerator and
1
the
denominator
10
2
3
2
3
I could not
fool you
twice. Huh.
You are good!
Problem # 1
First: Convert Mixed Numbers
to Improper fractions
Multiply the Denominator by the Whole Number
and add the Numerator
1
10
2
3
2
3
21
Do you want
to see that
again?
Problem #1
First: Convert Mixed Numbers
to Improper fractions
Multiply the Denominator by the whole Number
and add the Numerator
1
10
2
3
2
3
21
11
Problem # 1
Find
the
Least
Common
Denominator
• The Two is speaking and twoish and Three is
speaking threeish
• It’s like someone speaking Spanish and someone else
speaking English. No. No. They all must speak the
same language.
“Multiples of 2 and 3”
21
2
6
11
3
2 4 6
LCD
3 6
6
•
Problem # 1
Make
Equivalent
(Equal)
fractions
The Two is speaking and twoish and Three is
speaking threeish
• It’s like someone speaking Spanish and someone else
speaking English. No. No. They all must speak the
same language.
“Multiples of 2 and 3”
21
63
2
6
22
11
3
6
Problem # 1
Find
LCD
&
Make
Equivalent
fractions
• The Two is speaking and twoish and Three is
speaking threeish
• It’s like someone speaking Spanish and someone else
speaking English. No. No. They all must speak the
same language.
“Multiples of 2 and 3”
21
63
2
6
22
11
3
6
2 4 6
LCD
3 6
Problem # 1
Subtract numerators
keep same denominators
63
6
22
6
41
6
Problem # 1
Change improper fraction to mixed number
• Reduce fractions
63
6
6
22
6
41
6
6
41
36
5
Answer
5
6
5
6
Factors of 6
6
Factors of 5
5
1 5
6
1
6
2
3
Next Problem
Problem # 2
Convert Mixed Numbers
to Improper fractions
Multiply the Denominator by the Whole Number
and add the Numerator
3
1
1
3
7
8
10
15
Problem # 2
Find LCD & Make Equivalent fractions
• Make the denominators speak the same language
Multiples of 3 and 8
10
3
80
15
24
45
8
24
3
6
9 12 15 18 21 24
LCD
8 16 24
Problem # 2
Change improper fraction to mixed number
• Reduce fractions, if necessary
80
Since there are no common factors, the
fraction can not be reduced.
45
24
35
24
24
35
24
11
No common
factors
11
1
1
24
Answer
24
Factors of 24
Factors of 11
11
1
11
24
1
24
2
12
3
8
4
6
Next Problem
Problem # 3
Convert Mixed Numbers
to Improper fractions
Multiply the Denominator by the Whole Number
and add the Numerator
2
1
1
2
4
7
5
11
Problem # 7
Find LCD & Make Equivalent fractions
• Make the denominators speak the same language
Multiples of 2 and 7
5
2
35
11
14
22
7
14
2 4 6 8 10 12 14
LCD
7 14
Problem # 3
Subtract numerators keep same denominators
Change improper fraction to mixed number
Since this is not an improper fraction, then it does
not need to be changed to a mixed number.
35
14
• Reduce fractions, if necessary
Since there are no common factors, the
fraction can not be reduced.
22
14
13
14
No common
factors
1
13
13
14
Factors of 14
Factors of 13
13
Answer
14
1
14
2
7