Download Lesson 3.2- Organizing Fractions and Decimals KEY

November 17, 2011
Lesson 3.2:
Comparing and Organizing Fractions and Decimals
Focus: Use benchmarks, place value, and equivalent fractions to compare and
order fractions and decimals.
-5
-4
-3
-2
-1
1
0
2
3
5
4
Use the number line above:
a) Together, let's label the benchmarks 0, 0.5, 1, 1.5 and 2 on the
number line.
b) Name a fraction that is close to 1 but less than 1. Where would
it be on the number line?
c) Name a fraction that is even closer to 1 than the one you
have. Why is this fraction closer?
-4
-3
-2
-1
0
1
2
d) Find fractions
i) close to 0.5 but less than 0.5
ii) close to 0.5 but greater than 0.5
e) Where would 3 fit on the number line? Why?
20
f) Where would 8 fit on the number line? Why?
9
3
4
5
November 17, 2011
Explore- p. 91
In groups of 2 - use number lines, fraction circles,
and grid paper
Susan, Sasha and Kim sold chocolate bars as a fundraiser for their
choir. The bars were packaged in cartons, but sold individually.
Susan sold 2 2. Sasha sold 5 cartons. Kim sold 2.25 cartons.
3
2
a) Who sold the most? Show your work and explain your strategy.
b) What materials could you use to help you figure this out?
How are you able to find mixed fractions on a number line?
Sasha
Susan
Kim
November 17, 2011
Connect:
How could you compare the numbers without using materials?
EQUIVALENT FRACTIONS
- Find a _______________________________ for your fractions
Ex) 2/3, 1/2, 1/4
Converting to DECIMALS
Write each number as a ____________, then compare __________
2 2/3 =
5/2 =
=
2.25
How to change a mixed number to an improper fraction:
Ex1) 1 2
3
Ex2) 3 5
6
How to change an improper fraction to a mixed number:
Ex1) 11
6
Ex2) 15
2
November 17, 2011
Any fraction greater than 1 can be written as a mixed number.
The benchmarks 0, 1/2, and 1 can be used to compare the fraction
parts of mixed numbers.
Example 1a):
We can use benchmarks on a number line to order these numbers:
2/11, 2 3/8, 1 1/16, 14/9, 14/15
0
Example 1b):
Use benchmarks on a number line to order these numbers:
1 2/8, 3/6, 2 5/9, 1/8
0
November 17, 2011
Example 2:
Write these numbers in order from least to greatest using
equivalent fractions:
Must find a
common
demoninator
a)7/8
Common denominator: _____
b)9/8
c)1 1/4
d) 0.75
0
Example 3:
Write a fraction between 9/8 and 1 1/4
Step 1: Draw a number line
Step 2: Put numbers in a form that is the SAME (mixed numbers)
Step 3: Put numbers on a number line
Step 4: Choose a number that is in between them
0
November 17, 2011
Example 4:
We can use place value to order decimals:
7/8 =
9/8 =
Ones
1 1/4 =
Tenths
0.75
Hundredths
Thousandths
Least to greatest: __________________________________
Practice: p. 94 #1-5, 7-11
November 17, 2011
November 17, 2011