Transcript Grade 5 Big Idea 2 - ElementaryMathematics

Third Grade
Big Idea 2
Develop an
understanding
of fractions and
fraction
equivalence.
Why Fractions?
Because sometimes they’re the
only way to get your fair share…
This is particularly important
when it comes to cookies and
candy bars :)
Is this you (or someone you know)?
Consider this
concerning data…
Estimate 12 + 7 .
13
a) 1
 c) 19

8
b) 2
d) 21
When asked this question, only 24% of 13year olds and only 37% of 17-year olds
could estimate correctly.
Big Idea 2 Benchmarks
Assessed with MA.3.A.2.3
MA.3.A.2.1
Represent fractions, including fractions greater than
one, using area, set and linear models.
Area Model
•An area model is useful for representing scenarios that
involve wholes like cakes, candy bars, or pizzas
•Includes finding equal shares and finding the whole given part
of it.
I have 2, 16 inch pizzas that I
want to share with 4 friends
and me. How much pizza will
we each get if we share all of
the pizza equally?
This shape is onefourth of the whole.
Draw a picture of
what the whole
would look like.
Another Example:
Last night we had 3, 12-inch pizzas. The
picture below shows how much of the pizza
my family ate. How much pizza do we
have left?
FCAT 2.0
Sample
Test
Question
Answer: A
Let’s explore with color tiles!
Set Model
Used to show discrete objects such as buttons, marbles,
or muffins.
Must also include finding the whole given the fractional
part.
Julio has 12 train cars set up on his
3
track. This is of4 his collection. How
many train cars does he have?

Grab and Go Activity from
Lesson 7.7
Materials:
Grab and Go Activity from
Lesson 7.10
Sample Problem:
Fourteen students went to
the library to check out
books. Fourteen students
2
are 3 of the class. How
many students are in the
 class?
Linear Model
•The number line represents fractions with a linear model.
•Examples that fit this model include those with length and
distance.
MA.3.A.2.2
Describe how the size of the fractional part is related to the
number of equal sized pieces in the whole
MA.3.A.2.4
Use models to represent equivalent fractions including
fractions greater than one, and identify representations
of equivalence.
FCAT 2.0
Sample
Test
Question
Answer: D
Grab and Go Activity from
Lesson 8.2
Materials:
MA.3.A.2.3
Compare and order fractions, including fractions greater
than one, using models and strategies.
Fractions—For these problems, circle the greater
number of each pair and tell why it is greater.


1
6
1
3
1
4
3




3
6
3
8









1
7
2
7
3
1
2
1
10
7
7
8
5
6
Strategies to Compare/Order
Fraction
•When the whole numbers are different, you only have to
compare the whole numbers.
1
2
4

>

1
1
2
Strategies to Compare/Order
Fraction
•When the numerator is the same, look at the size of the
pieces in the denominator.
3
5

>

3
8
Strategies to Compare/Order
Fraction
•Use benchmark numbers.
3
8
<
Think: 3 is less than half of the
denominator so the fraction is less
than 1/2


3
5
Think: 3 is more than half of the
denominator so the fraction is more
than 1/2
Strategies to Compare/Order
Fraction
•Compare missing pieces
7
8
>
Think: 1/8 is missing.

4
5
Think: 1/5 is missing. Since 1/5 is a
larger missing piece than 1/8 then,

Grab and Go Activity from
Lesson 8.5
FCAT 2.0
Sample
Test
Question
Answer: A
FCAT 2.0
Sample
Test
Question
Answer: H
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