Subtract Fractions Calculator
Enter whole numbers for mixed fractions. Use 0 if a value has no whole part.
Example Data Table
| First Fraction | Second Fraction | LCD | Simplified Result | Decimal |
|---|---|---|---|---|
| 3/4 | 1/8 | 8 | 5/8 | 0.625000 |
| 2 1/3 | 5/6 | 6 | 3/2 | 1.500000 |
| 7/9 | 4/9 | 9 | 1/3 | 0.333333 |
| 1 5/8 | 2/3 | 24 | 23/24 | 0.958333 |
Formula Used
Core subtraction rule:
a/b − c/d = (ad − bc) / bd
For easier simplification, the calculator first finds the least common denominator:
LCD = LCM(b, d)
Then it rewrites both fractions with the LCD, subtracts numerators, and reduces the final fraction using the greatest common divisor.
How to Use This Calculator
- Enter the first fraction using the whole number, numerator, and denominator fields.
- Enter the second fraction in the same way.
- Keep whole number as 0 for simple fractions like 3/4.
- Select whether you want decimal and mixed number outputs.
- Press Subtract Fractions to view the result above the form.
- Use the export buttons to save the result as CSV or PDF.
Why this calculator is useful
This calculator handles simple fractions, mixed numbers, and unlike denominators in one place. It shows the least common denominator, converted fractions, simplified answer, optional mixed form, and decimal value. That makes it useful for classroom practice, homework checking, worksheets, and quick revision.
FAQs
1. Can this calculator subtract unlike fractions?
Yes. It finds the least common denominator automatically, converts both fractions, subtracts the numerators, and simplifies the final answer.
2. Does it work with mixed numbers?
Yes. Enter the whole number in its own box, then enter the fractional part. The calculator converts mixed numbers into improper fractions before subtraction.
3. What happens if the answer is negative?
The result section labels it as a negative result and still shows the simplified fraction, plus optional decimal and mixed number output.
4. Why must the denominator be nonzero?
A fraction with denominator zero is undefined. The calculator blocks that input and shows an error message instead of calculating an invalid result.
5. Does it simplify the answer automatically?
Yes. After subtraction, the calculator reduces the fraction using the greatest common divisor so the answer appears in lowest terms.
6. Can I download my result?
Yes. Use the CSV button for spreadsheet-friendly output or the PDF button to create a neat printable report of the result section.
7. Is this useful for students and teachers?
Yes. It supports fast checking, worked-step review, printable summaries, and practice examples, making it helpful for lessons, assignments, and revision.