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Last updated on September 1, 2025
The mathematical operation of finding the difference between a fraction and a whole number or vice versa is known as the subtraction of fractions with whole numbers. It is an essential skill that helps simplify calculations and solve problems involving fractions and whole numbers.
Subtracting fractions with whole numbers involves converting the whole number to a fraction and then performing the subtraction.
This process requires a common denominator to combine the terms effectively.
There are key components to consider when subtracting fractions with whole numbers:
Numerators: These are the numbers above the fraction line.
Denominators: These are the numbers below the fraction line.
Whole Numbers: These are integers without fractional parts.
When subtracting fractions with whole numbers, follow these steps:
Convert the whole number: Change the whole number into a fraction by giving it the same denominator as the fraction.
Subtract the numerators: Once the whole number is in fraction form, subtract the numerators while keeping the denominator the same.
Simplify the result: Reduce the resulting fraction to its simplest form if possible.
The following are methods for subtracting fractions with whole numbers:
Method 1: Convert and Subtract To apply this method, use the following steps:
Step 1: Convert the whole number to a fraction with the same denominator as the given fraction.
Step 2: Subtract the numerators, keeping the denominator constant.
Step 3: Simplify the resulting fraction if possible.
Example:
Question: Subtract 3 from 7/4
Step 1: Convert 3 to 12/4 (since 4 is the denominator of the fraction).
Step 2: Subtract: 7/4 - 12/4 = -5/4.
Step 3: The result is -5/4, which is already simplified.
Method 2: Mixed Number Conversion
This method involves converting the subtraction into a mixed number form:
Step 1: Convert the whole number to a mixed number that can be easily subtracted from the fraction.
Step 2: Perform the subtraction.
Example: Subtract 2 from 9/3
Solution: Convert 2 to 6/3 (since 3 is the denominator of the fraction). 9/3 - 6/3 = 3/3 = 1
Subtraction of fractions with whole numbers has certain properties:
Subtraction is not commutative Changing the order changes the result, i.e., A - B ≠ B - A.
Subtraction is not associative You cannot regroup in subtraction, as it affects the outcome.
(A − B) − C ≠ A − (B − C)
Subtraction involves equivalent fractions To subtract, convert whole numbers into fractions with equivalent denominators.
Subtracting zero Subtracting zero from a fraction or whole number leaves it unchanged: A - 0 = A.
Here are some tips to efficiently subtract fractions with whole numbers:
Tip 1: Always convert whole numbers to a fraction with the same denominator as the fraction before subtracting.
Tip 2: Simplify your answer by dividing the numerator and denominator by their greatest common divisor.
Tip 3: Double-check your work by adding the result back to the subtracted portion to see if you get the original number.
Students often forget to convert the whole number to a fraction with an equivalent denominator, leading to incorrect results.
Convert 5 to 10/2 (same denominator as 3/2). 3/2 - 10/2 = -7/2
Subtract 4 from 11/3
-1/3
Convert 4 to 12/3. 11/3 - 12/3 = -1/3
Subtract 6 from 17/4
-7/4
Convert 6 to 24/4. 17/4 - 24/4 = -7/4
Subtract 2 from 5/6
-7/6
Convert 2 to 12/6. 5/6 - 12/6 = -7/6
Subtract 7 from 9/8
-47/8
Subtraction with fractions and whole numbers can be tricky, leading to common errors. Being aware of these can help in avoiding them.
Hiralee Lalitkumar Makwana has almost two years of teaching experience. She is a number ninja as she loves numbers. Her interest in numbers can be seen in the way she cracks math puzzles and hidden patterns.
: She loves to read number jokes and games.