MSM6
Lesson 5-9
Renaming to Subtract
Mixed Numbers
Vocabulary
• Renaming or equivalent fractions – Changing a fraction or
a mixed number into an equivalent fraction, mixed
number with an improper fraction, or improper fraction.
• Regrouping (Borrowing) to complete a fraction
subtraction.
• Mixed Number – A number that contains both a whole
number greater than 0 and a fraction.
• Equivalent Fractions – Fractions that name the same
amount or part.
• Unlike Fractions – Fractions with different denominators.
Subtracting fractions with regrouping
To subtract fractions that require regrouping, there are four steps you must follow:
1.Rename with common denominators
2.Regroup the first fraction
3.Subtract the whole numbers and numerators
4.Simplify (if necessary)
The problem
Rename with common
denominators
Regroup the first fraction
Subtract the whole numbers
and fractions
Simplify (if necessary)
1 1
2 1 
3 2
2
1 2
1 3
2 3
1
 2 1 
3 2 23
6 6
2
2 6 8
2 1  1
6
6 6
6
8 3
8 3
5 5
1  1  (1  1)  (  )  0  
6 6
6 6
6 6
5
6
Skills – Renaming Mixed Numbers
• Rename 6 5 as
12
5
7
6 2
12
12
5
12 5
17
5 1  5    5
12
12 12
12
• Subtract the whole numbers and the fractions.
17
7
17 7
10
10
5  2  (5  2)  (  )  3   3
12
12
12 12
12
12
• Write the answer in simplest form.
10
5
3 3
12
6
Skills – Word Problem Application
• Dave is recovering an old couch and cushions. He
determines that he needs 17 yards of fabric for the
5
9
job. If Dave uses 6 yards of fabric to cover the
couch frame, how many more yards does he need?
– Write 17 as a mixed number with the fraction’s
denominator of 6. Rename 17 as:
17  16 
6
6
 16
6
6
– Subtract the whole numbers and the fractions.
6
5
6 5
1
1
16  9  (16  9)  (  )  7   7
6
6
6 6
6
6
– Simplify if necessary
1
7
6
Homework
• (L5-9) Renaming to Subtract Mixed Numbers,
pp. 252 – 255
• Homework - Online Quia Other Quizzes,
MSM6 Lesson 5-9, Renaming to Subtract
Mixed Numbers, problems 1-4.
• OR
• Homework – Textbook, Practice and Problem
Solving, p. 254, problems 16, 20, 24, and 28.