1. Unit 2 Fraction Operations
Pre-Alg.

2. 1. Name two fractions equivalent to 3/4
Unit 2: Fractions!
9/20
DCN # 150
Bell Ringer
Concept Builder:
Review strategies for
adding and subtracting
fractions and mixed
numbers.
Direct Instruction or
Explorations:
Notes on fraction/mixed number +/-
Practice
Independent Work/hw:
Worksheet
Assessment:
Teacher obs.
Bellringer
1. Name two fractions equivalent to 3/4
Write in standard form
5.06 x 10-7
3. Volume = ____
3.2 ”
5.1” 4”
in3

3. Review of fractions- What is a fraction?
We all learned that a fraction was part of a whole.
That’s true but fractions are also-
A ratio of two numbers
An incomplete division problem
A way to compare two numbers
If one slice is eaten what remains? 1 2
2/3 ? 3

4. 52 2/3 2/12 Both have the digit 2 but the 2 has a different
different value
here. 52
Both have the digit 2 but the 2 has a different
value in 27 than in 52. It’s place value is
larger!
2/ /12
Would you rather have 2/3 of a pizza or 2/12?
Both numbers have a 2 in them!
The 2 has a
different value
here as well!
A new way to think about fractions
Numerator Digit
Denominator Place Value

5. If you still eat 1/3 of the pizza, what is left on
Eating an equal amount of the same size of pizza sliced into 12 pieces.
If you still eat 1/3 of the pizza, what is left on
the 12 slice pizza? How many smaller slices?
3 Slices Slices 8
2 = ?
2 x 4 =
3 x

6. Two thirds of seventh graders write with
Same problem worded differently….
Two thirds of seventh graders write with
mechanical pencils. If we select 12
seventh graders at random, how many
would prefer to write with a mechanical
pencil? 8
2 = ?
2 x 4 =
3 x

7. 2 12 21 Adding and subtracting fractions and mixed numbers
Find a common denominator +
2. Add the fraction and whole
numbers.
3. Reduce your answer 2 12 21

8. 2 3 5 Renaming in subtraction Borrow from the whole number.7
Borrow from the whole number.
Add the denominator to the numerator to make the new numerator.
Subtract. 3 2 5

9. 2. Write in scientific notation 304000000
Multiplying Fractions
9/21
DCN # 149
Bell Ringer
Concept Builder:
Review strategies
numbers. for multiplying fractions
Direct Instruction or
Explorations:
Check HW
Round Robin problems
Independent Work/hw:
Assessment:
Teacher obs.
Bellringer
/5 – 5 5/7 =
2. Write in scientific notation
3. Compare √ 34 _____ 650%
/35
x 108
3. <

10. Multiplying with numbers greater than 1 result in products larger than their factors. For example-
Think “3 sets of 4 equals 12 ”
X = OF
Multiplying with fractions less than 1 result in products smaller than one or more of their factors. For example- ½ x 4 = ½ x ¼ = 1/8
Think “ ½ set of 4 equals 2”

11. 1 2 1 x 2 = 2 1 x 5 = 5 5 1 Reduce first if possible
Multiplying fractions and mixed numbers.
Reduce first if possible
Multiply the numerators
Multiply the denominators 1 5 2 1
1 x 2 =
1 x 5 =

12. Change mixed numbers to improper fractions. Reduce if possible
Multiply numerators and denominators.
Multiplying mixed numbers

13. Dividing Fractions
9/22
DCN # 148
Bell Ringer
Concept Builder:
Understand the meaning
of multiplying fractions;
applying the
multiplication algorithm
Direct Instruction or
Explorations:
Demonstrate fraction division using modeling
Notes on the algorithm
Class practice text
pp 144 problems 1-27
Independent Work/hw:
Worksheet
Assessment:
Teacher obs.
Bellringer
1. Under what conditions can I multiply a number by a fraction and get a larger number? Explain.
2. 1/5 – 5/6 =
/ /5 =

14. One way to divide fractions. . .
4 ÷ ½ = 8
Another way …

15. Dividing fractions and mixed numbers
Change any mixed numbers to improper fractions.
2. Keep, change, flip to make it a multiplication problem.
3. Reduce first if possible and multiply.

16. The easiest way . . .
A number multiplied by it’s multiplicative inverse equals 1.
For example:
Multiplicative inverse
*Also called the
reciprocal
Why is this important?
In the operation of division, multiplying with the divisor’s multiplicative inverse results in the same answer. For example, 4 ÷ 2 = 4 x ½
So when you have a division problem with fractions or mixed numbers, keep change flip and make it a multiplication problem.

17. 199 is between perfect squares 196 and 225 or
Multiplying and Dividing
Fractions
9/23
DCN # 147
Bell Ringer
Concept Builder:
Multiplying mixed
numbers by applying the
multiplication algorithm
Direct Instruction or
Explorations:
Check HW
Drill and kill problems
Independent Work/hw:
Worksheet
Assessment:
Teacher obs.
800/40=20
783/37=21.2
Bellringer
1. Quickly estimate: 783 ÷ 37
2. 2/5 – 5/7 =
3. Estimate √199
-11/35
199 is between perfect squares
196 and or
14 < √199 < 15 but closer to 14 than
15 so estimate 14.1 or 14.2

18. Place in order from least to greatest | -5 + 3 | -17 -√3 9 x 10-3
Multiplying and Dividing Fractions
9/28
DCN # 145
Bell Ringer
Concept Builder:
Applying the
multiplication and
division algorithm
Direct Instruction or
Explorations:
Check homework
Amateur Arch.
Independent Work/hw:
Worksheet
Assessment:
Teacher obs.
Bellringer:
Place in order from least to greatest
| | √ x 10-3

19. Bellringer: Test Review Choose the correct answer for
Multiplying and Dividing Fractions
9/29
DCN # 144
Bell Ringer
Concept Builder:
Applying the
multiplication and
division algorithm to
fractions and mixed
numbers
Direct Instruction or
Explorations:
Review fraction operations on desk
Word problems in groups
Independent Work/hw:
Worksheet
Assessment:
Teacher obs.
Quiz grade
Bellringer: Test Review
Choose the correct answer for
A. 2 ½ B ½ C / D /32
2. Choose the correct answer for
A B C / D /4 3.
4. What is 4/7 of 28?
5. Babs had 12 ½ yards of ribbons that she cut into pieces ¾ yd. long. How many pieces did she have?

20. Renaming in subtraction