Calculator
Use one common denominator. Add at least two numerators. Blank numerator fields are ignored.
Plotly Graph
This chart compares each entered numerator and the total numerator used in the final fraction.
Example Data Table
| Fractions | Common Denominator | Added Numerators | Unsimplified Result | Simplified Result | Decimal |
|---|---|---|---|---|---|
| 1/8 + 2/8 + 3/8 | 8 | 1 + 2 + 3 = 6 | 6/8 | 3/4 | 0.75 |
| 2/9 + 4/9 | 9 | 2 + 4 = 6 | 6/9 | 2/3 | 0.666667 |
| 5/12 + 1/12 + 4/12 | 12 | 5 + 1 + 4 = 10 | 10/12 | 5/6 | 0.833333 |
| 7/10 + 2/10 + 1/10 | 10 | 7 + 2 + 1 = 10 | 10/10 | 1/1 | 1.0 |
Formula Used
When denominators are the same, add only the numerators. Keep the denominator unchanged.
Formula:
a/d + b/d + c/d = (a + b + c)/d
After finding the sum, simplify the fraction by dividing the numerator and denominator by their greatest common divisor.
How to Use This Calculator
- Choose how many fractions you want to add.
- Enter one common denominator.
- Type each numerator in the visible numerator fields.
- Click Add Fractions.
- Read the unsimplified result, simplified fraction, mixed number, decimal, and percent.
- Use the export buttons to save the current result as CSV or PDF.
FAQs
1. What are like denominators?
Like denominators are equal denominators. Fractions such as 2/7 and 5/7 have like denominators because both use 7 below the fraction bar.
2. Why do we only add the numerators?
Equal denominators mean the parts are the same size. You only count how many parts you have, so the numerator changes while the denominator stays fixed.
3. Does the denominator ever change?
The common denominator stays the same during addition. It may change only after simplification, because both numerator and denominator can be divided by a common factor.
4. Can this calculator simplify the result?
Yes. It automatically reduces the result to lowest terms by finding the greatest common divisor of the final numerator and denominator.
5. Can I enter negative numerators?
Yes. Negative numerators are allowed. This helps with signed fraction practice and algebra problems where subtraction is written as adding a negative fraction.
6. What if I leave some numerator fields blank?
Blank numerator fields are ignored. The calculator only uses numeric entries from the visible fraction slots.
7. Why does the calculator show decimal and percent values?
Decimal and percent views help compare the fraction with other number formats. They are useful for checking reasonableness and building stronger number sense.
8. Can I use this for unlike denominators?
No. This page is designed for like denominators only. Unlike denominators must be converted to a common denominator before addition.