Fraction Basics Lesson

Fraction
Basics
Review

Fractions
Vocabulary
A fraction such as 7/4 has two numbers.

●Numerator: top number/ the number of
parts we have.

●Denominator: bottom number/ the number
of parts the whole is divided into.

Parts of a Fraction

●Proper Fractions: has a numerator
smaller than the denominator.

●Mixed Number: combines both whole
numbers and fractions .

●Improper Fractions: a numerator larger
than the denominator.

Types of Fractions

Section 1: Finding the Least
Common Denominator
(LCD)

When adding or subtracting fractions, there MUST be a commondenominator so that the
fractions can be added or subtracted. Common denominators are the same number on
the bottom of fractions.

Each set of fractions has many common denominators; we will find the smallest number
that one or both fractions will change to.

Find the LCM of the denominators 2 and 4.

Since 4 is the LCM of 2 and 4, the LCD=4.

Note: You may have noticed that multiplying the denominators together also gets a common
denominator. This method will always get a common denominator but it may not get a lowest
common denominator.

Multiple Choice

Which of these numbers could NOT be a common denominator for these two fractions?
2/4   and   3/8

• 32
• 12
• 8
• 24

Multiple Choice

Find the least common denominator.
$$\frac{7}{9}\ and\ \frac{1}{6}$$  

• 6

• 9

• 54

• 18

Multiple Choice

Which of these numbers could NOT be a common denominator for these three fractions?
1/3   and 2/5   and   3/10

• 15
• 30
• 60
• 90

Multiple Choice

What is the least common denominator of 2/6 and 7/8?

• 36
• 8
• 18
• 24

Multiple Choice

What is the least common denominator for 1/3 + 1/2 + 1/4

• 8
• 6
• 9
• 12

Section 2: Creating
Equivalent Fractions

An equivalent fraction is obtained by multiplying both the numerator
and denominator of the fraction by the same number.

An equivalent fraction can also be obtained by dividing both the
numerator and denominator of the fraction by the same number.

Multiple Choice

Which of the following fractions are equivalent?

• $$\frac{1}{2}=\frac{2}{5}$$  

• $$\frac{3}{4}=\frac{8}{12}$$  

• $$\frac{1}{3}=\frac{3}{12}$$  

• $$\frac{2}{3}=\frac{6}{9}$$  

Multiple Choice

True or False:

2/3 = 18/27

• True

• False

Multiple Select

Select all fractions equivalent to  $$\frac{2}{6}$$  .

• $$\frac{1}{3}$$  

• $$\frac{5}{10}$$  

• $$\frac{4}{12}$$  

• $$\frac{2}{8}$$  

Section 3: Reducing
Fractions

A fraction should be reduced any time both the top and bottom
number can be divided by the same smaller number. This way you can
be sure the fraction is as simple as it can be.

When you divide both the top and bottom numbers of a fraction by the
same the value of the fraction doesn’t change, only the size of the
numbers used to express it.

Multiple Choice

Reduce 8/32

• 1/4

• 4/16

• 1/2

Multiple Choice

Reduce 20/36

• 5/7

• 5/12

• 5/9

Section 4: Converting Improper Fractions to
Mixed Numbers

An improper fraction is one in
which the numerator is larger than
the denominator. Your final
answers should NEVER be written
as improper fractions. If you have
an improper fraction, convert it to a
mixed number.

Section 5: Converting Mixed Numbers
to Improper Fractions

Converting a mixed
number to an improper
fraction may be useful in
some instances.

Multiple Choice

$$\frac{61}{9}=\ ?$$  

• $$6\frac{5}{9}$$  

• $$7\frac{2}{9}$$  

• $$6\frac{7}{9}$$  

• $$5\frac{7}{9}$$  

Multiple Choice

$$\frac{35}{6}=\ ?$$  

• $$5\frac{1}{6}$$  

• $$5\frac{5}{6}$$  

• $$6\frac{1}{6}$$  

• $$5\frac{2}{6}$$  

Multiple Choice

Convert this mixed number to an improper fraction.

• $$\frac{35}{9}$$

• $$\frac{36}{9}$$
  

• $$\frac{24}{8}$$
  

• $$\frac{27}{9}$$
  

Multiple Choice

Change to an improper fraction.

• 24/4
• 35/4
• 11/3
• 28/3

Multiple Choice

Convert  ⁴⁵/₁₂  to a Mixed Number.

• 4  ⁵/₁₂
• 3  ⁹/₁₂
• 3  ³/₄
• 9  ³/₁₂

Multiple Choice

Convert $$22\frac{1}{2}$$  to an improper fraction.

• $$\frac{45}{2}$$  

• $$\frac{22}{2}$$  

• $$\frac{1}{22}$$  

• 5