Fraction Review
Unit 2 Lesson 1
Mental Math
An hour is what fraction of a day?
1/24
A minute is what fraction of an hour?
1/60
A second is what fraction of an hour?
1/3600
Mental Math
½ hour is how many minutes?
30 mins.
¾ of an hour is how many minutes?
45 mins.
⅓ of an hour is how many minutes?
20 mins.
⅙ of an hour is how many minutes?
10 mins.
Math Message
With a partner, describe two situations in which
you would use fractions. Be prepared to share!
Why fractions?
● Fractions were invented to express numbers that are
between whole numbers
● can show measure between whole numbers on
rules and scales
● can name a part of a whole object (example: part of
a cake or pizza)
● can name a part of a collection of objects (example:
part of the eggs in a carton)
THE WHOLE
● Most fractions are fractions of something. That
something is referred to as the whole, or ONE, or
with measurements as the unit.
Think about this...
If I give you half of my CD collection, how many
CDs will I have left?
● The answer depends on the WHOLE… can
you identify the whole?
● The CD collection is the WHOLE, so the
answer depends on how many CDs I have.
Basic Fraction Ideas
● can be written horizontally as a/b
● can be written vertically as
numerator: number of parts
under consideration
denominator: the number of
equal parts the whole is
divided into
Fractions in which the numerator and denominator
are the same are equivalent (equal) to 1.
Why is this true?
The number of equal parts named by the
numerator is the same as the number of equal
parts named by the denominator that make the
whole.
If i have 4/4 of something, I have a whole!
How would you solve the following problem?
Julia came home from school to find 3 fresh
homemade lemon squares. She had 3 friends with
her. The 4 friends decided to share the 3 lemon
squares equally. How much of a whole lemon
square did each girl get?
Draw pictures to help solve the problem!
If we wanted to create a
number sentence to
represent this problem,
what would it look like?
3÷4=¾
Let’s try another one!
Shane had a pizza party with 4 of his friends. He
ordered 2 extra large pizzas. If the pizzas were
shared equally, how much pizza did each person
get?
2÷5=⅖
Each friend would get ⅖
of a pizza.
Using Fraction Notation for Division
Solving Parts and Whole Problems
Journal Page &
20 Counters
There are 3 types of problems...
● #1&#2 : the whole and a part are given; the
fraction needs to be named
● #3, #4, #7 : the whole is given and the fraction is
named; the part needs to be found
● #5, #6, #8 : a part is given and the fraction is
named; the whole needs to be found
Solving Parts and Whole Problems
Journal Page &
20 Counters
If 1/10 of a set is 2 counters….
● 2/10 would equal 4 counters (2x2=4)
● 4/10 would equal 8 counters (4x2=8)
● How many counters are in the set? 20 counters
Complete the practice problems with a partner using
the counters.