 Online Calculators

$= \frac{9}{80}$Showing the Work:
With unlike denominators find the Least Common Denominator (LCD)

LCD = 80

Multiplying numerators and denominators to get the LCD in all fraction denominators$= \frac{-1 \times 16}{5 \times 16} - \frac{1 \times 5}{16 \times 5} + \frac{3 \times 10}{8 \times 10}$Then rewriting the equation with the equivalent fractions$= \frac{-16}{80} - \frac{5}{80} + \frac{30}{80}$With like denominators we can operate on just the numerators$= \frac{-16 - 5 + 30}{80}$$= \frac{9}{80}$

## Calculator Use

Add and subtract proper and improper fractions with this calculator and see the work involved in the solution.

Select the number of fractions in your equation and then input numerators and denominators in the available fields. Click the Calculate button to solve the equation and show the work.

You can add and subtract 3 fractions, 4 fractions, 5 fractions and up to 9 fractions at a time.

## How to Add and Subtract Fractions

### When the Denominators are the Same

When fractions have the same denominators we simply add or subtract the numerators as indicated and place the result over the common denominator. If necessary we can simplify the fraction to lowest terms or a mixed number.

### When the Denominators are Unlike or Different

When fractions have unlike denominators the first step is to find equivalent fractions so that all of the denominators are the same. We find the Least Common Denominator (LCD) then rewrite all fractions in the equation as equivalent fractions using the LCD as the denominator. When all denominators are alike, simply add or subtract the numerators and place the result over the common denominator. The resulting fraction can be simplified to lowest terms or written as a mixed number.

## How to Work With Negative Fractions

When an equation calls for adding a negative fraction, we can rewrite the equation as subtracting a positive fraction. Likewise, if the equation calls for subtracting a negative fraction, this is the same as adding a positive fraction and can be rewritten this way. This calculator rewrites negative fractions when it shows the work involved in finding the answer.

### Simplifying Operations on Negative Numbers

Whether you are working with fractions, whole numbers or decimals, use these guidelines when adding and subtracting positive and negative numbers.

Original

Operation
Operand Sign
+
+
+
-
Subtracting a Positive Number
+
Subtracting a Negative Number
-
Changes to
Operation
Operand Sign

+
+
+
Subtracting a Positive Number
+
Subtracting a Positive Number
+
+