
Mixed Numbers and
Improper Fractions
A mixed number is a combination of a whole
number and a fraction. For example, if you have two
whole apples and one half apple, you could describe this
as 2 + 1/2 apples, or 21/2 apples.
Writing Mixed Numbers as Fractions
This mixed number can also be expressed as a
fraction. Each whole apple contains two half apples.
Your two whole apples are also four half apples. Four
half apples plus one half apple is five half apples. So
you have 5/2 apples.
To put this another way: to turn a mixed number
into a fraction, multiply the whole number by the
denominator (the bottom part), and add the result to the
numerator (the top part).
21/2 = ?
Multiply the whole number by the denominator.
The whole number is 2.
The denominator is 2.
2 x 2 = 4.
Add the result to the numerator:
The numerator is 1.
4 + 1 = 5
The numerator is 5. The denominator remains 2.
21/2 = 5/2
Another Example
Let's try another example:
52/3 = ?
Multiply the whole number by the denominator.
The whole number is 5.
The denominator is 3.
5 x 3 = 15.
Add the result to the numerator:
The numerator is 2.
15 + 2 = 17
The numerator is 17. The denominator remains 3.
52/3 = 17/3
Proper and Improper Fractions
A fraction in which the numerator is smaller than the
denominator, like 1/3 or 2/5 is
called a proper fraction. A fraction in which the
numerator is larger than or equal to the denominator,
like 5/2, 17/3, or 6/6
is called an improper fraction. (To put it
another way, a fraction with a value less than 1 is a
proper fraction. A fraction with a value greater than or
equal to 1 is an improper fraction.)
As we have shown above, mixed numbers can be written
as improper fractions. Similarly, improper fractions can
be written as mixed numbers.
Writing Improper Fractions as Mixed Numbers
To write an improper fraction as a mixed number,
divide the numerator (top part) by the denominator
(bottom part). The quotient is the whole number, and the
remainder is the numerator.
How would you express 17/4 as a mixed
number?
Divide the numerator by the denominator:
17 ÷ 4 = 4, with a remainder of 1
The quotient, 4, is the whole number. The
remainder, 1, is the numerator. The denominator
remains 4.
17/4 = 41/4
Two More Examples
Let's try another couple of examples:
14/9 = ?
Divide the numerator by the denominator:
14 ÷ 9 = 1, with a remainder of 5
The quotient, 1, is the whole number. The
remainder, 5, is the numerator. The denominator
remains 9.
14/9 = 15/9
If there is no remainder, just take the quotient as
the whole number:
20/5 = ?
Divide the numerator by the denominator:
20 ÷ 5 = 4
The quotient, 4, is the whole number. There is no
remainder.
20/5 = 4
|