Addition and Subtraction of Mixed Numbers

In this article, we will learn how to add and subtract mixed numbers easily, quickly, and effortlessly.

The solution to add and subtract mixed numbers consists of 3 steps:

Convert the mixed number into an equivalent fraction, a fraction with only a numerator and denominator without whole numbers.

How do you convert a mixed number into an equivalent fraction?

Multiply the whole number by the denominator. To the result, you will add the numerator. The final result will be recorded in the new numerator.

The denominator will remain the same.

Convert the mixed number $3 \frac {4}{5}$ into an equivalent fraction

Solution:

Find the numerator:

We will multiply the whole number: $3$ by the denominator $5$ and then add the numerator $4$. We will obtain:

$3\times 5+4=19$

We obtained $19$ and therefore this is what is written in the numerator.

The denominator will remain the same as the original: $5$.

Therefore, we will obtain that:

$3 \frac {19}{5}= \frac {4}{5}$

Find a common denominator (usually by multiplying the denominators)

Reminder:

Using the method of multiplying the denominators, we multiply the first fraction by the denominator of the second fraction and the second fraction by the denominator of the first fraction.

Remember to multiply both the numerator and the denominator.

Find a common denominator for the fractions: $3 \over 4$ and $2 \over 5$

Solution:

We multiply the fraction $3 \over 4$ by $5$ the denominator of the second fraction and obtain $15 \over 20$

We multiply the fraction $2 \over 5$ by $4$ the denominator of the first fraction and obtain: $8 \over 20$

The common denominator is $20$.

Sum or subtract numerators only. The denominator will remain the same and will be written once in the final result.

$\frac {3}{13}+\frac {9}{13}=\frac {12}{13}$

Solution:

When the denominator is identical, we will only add the numerators and obtain: $\frac {12}{13}$

Now, after having learned all the steps for the solution, we will practice exercises on adding and subtracting mixed numbers:

$2 \frac {3}{4}+1 \frac {2}{6}=$

Solution:

Let's convert the two mixed numbers in the exercise into equivalent fractions:

$2 \frac {3}{4}= \frac {2 \times 4+3}{4}=\frac {11}{4}$

$1 \frac {2}{6}= \frac {6 \times 1+2}{6}=\frac {8}{6}$

Let's write the exercise again:

$\frac{11}{4}+\frac{8}{6}=$

We find a common denominator by multiplying the denominators and we obtain:
$\frac {66}{24}+\frac {32}{24}=$

We will only add the numerators and obtain:

$\frac {66}{24}+\frac {32}{24}= ​​\frac {98}{24}$

$4 \frac {1}{5}-2 \frac {4}{5}=$

Solution:

Convert the two numbers into equivalent fractions:

$4 \frac {3}{6}= \frac {4 \times 6+3}{6}=\frac {27}{6}$

$2 \frac {1}{5}= \frac {2 \times 5+1}{5}=\frac {11}{5}$

Let's write the exercise again:

$\frac{27}{6}-\frac{11}{5}=$

We find a common denominator by multiplying the denominators and we get:

$\frac{135}{30}-\frac{66}{30}=$

We will only subtract the numerators and obtain:

$\frac {135}{30}-\frac {66}{30}=\frac {69}{30}$