subtract fractions

Subtract Fractions: Understanding the Basics


Learn how to subtract fractions step-by-step with real-life examples. Avoid common mistakes and understand the practical applications of subtracting fractions. Subtracting fractions is a fundamental math concept often taught in elementary and middle school. It involves finding the difference between two fractions by removing the smaller fraction from the larger one. This article will explore the basics of subtracting fractions, real-life examples, and frequently asked questions.

How to Subtract Fractions

To subtract fractions, you must have a basic understanding of fractions and how to find the lowest common denominator (LCD). The LCD is the smallest multiple that two or more fractions share and ensures that the fractions have the same denominator before subtracting. Here are the steps to subtract fractions:

  1. Find the fraction’s LCD by finding the denominator’s least common multiple.
  2. Reverse the fractions to equivalent fractions with the LCD as the denominator.
  3. Subtract the numerators of the fractions.
  4. Simplify the resulting fraction, if possible.

For example, let’s subtract 1/3 from 1/2:

  1. The LCD of 2 and 3 is 6.
  2. Convert 1/2 to 3/6 and 1/3 to 2/6.
  3. Subtract the numerators: 3/6 – 2/6 = 1/6.
  4. Simplify the resulting fraction: 1/6 is already in its simplest form.

Therefore, 1/3 subtracted from 1/2 equals 1/6. Get More Info

Real-life Examples

Subtracting fractions is not just a theoretical concept but is also used in real-life situations. Here are a few examples:


Cooking involves measuring ingredients and adjusting the quantities to fit the recipe’s needs. If a recipe calls for 3/4 cup of flour and you only have 1/2 cup, you must subtract 1/2 from 3/4 to determine how much more flour is required.

3/4 – 1/2 = 1/4 cup of flour needed


Subtracting fractions is also useful when dealing with time. For example, if you need to know how much time is left until a particular event, you can subtract the current time from the event’s starting time.

If an event starts at 2:30 PM and it is currently 1:45 PM, how much time is left until the event begins?

2:30 PM – 1:45 PM = 45 minutes left until the event starts


Subtracting fractions is also useful when dealing with money. For example, if you need to determine the difference between the cost of two items, you can remove the more nominal cost from the larger one.

If an item costs $5.75 and another costs $3.25, what is the difference in cost?

$5.75 – $3.25 = $2.50 difference in cost

Common Mistakes to Avoid When Subtract Fractions

Subtracting fractions can be tricky, and mistakes are common. This section will explore some common mistakes to avoid when subtracting fractions. For example, forgetting to find the LCD, only subtracting the numerators, or not simplifying the resulting fraction.

Subtract Fractions with Unlike Denominators

Subtracting fractions with unlike denominators requires finding the LCD before removing it. This section will provide step-by-step instructions on how to subtract fractions with unlike denominators and provide real-life examples. great post to read about Little Alchemy 2.

Subtracting Mixed Numbers

Subtracting mixed numbers involves converting them to improper fractions before finding the LCD and removing them. This section will explain how to remove mixed numbers and provide real-life examples, such as measuring ingredients for a recipe.

Real-life Applications of Subtract Fractions

Subtracting fractions is not just a theoretical concept but has real-life applications. This section will explore how removing bits can be used in everyday life, such as measuring cooking ingredients or calculating travel distances. We’ll also look at how subtracting fractions is used in various professions, such as carpentry and engineering.


What if the denominators are already the same?

If the denominators are the same, skip step 1 and go directly to step 3.

What if the numerator of the smaller fraction is larger than the numerator of the more significant fraction?

If the numerator of the smaller fraction is larger than the numerator of the more significant fraction, the resulting fraction will be negative. In this case, you can switch and subtract the fractions in the opposite order.

Can you subtract mixed numbers?

Yes, you can subtract mixed numbers by converting them to improper fractions and following the same steps as subtracting common fractions.

Subtract Fractions Table

Fraction 1Fraction 2Difference

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