Convert every whole number to a fraction
Write each whole over the expression’s denominator: in 2 + 1/3, the 2 becomes 6/3. Mixed numbers convert to improper fractions the usual way.
Adding fractions
How to Write an Expression as a Single Fraction
“Write as a single fraction” asks for one bar carrying the whole expression — no loose whole numbers, no mixed form. Convert the wholes, match the denominators, combine the numerators: 2 + 1/3 = 6/3 + 1/3 = 7/3.
- one fraction, one bar
- rewrite the whole over the denominator
- common denominators first
- improper answers are fine
Visual addition tool
See how fraction parts become ready to add
Start with one problem, make the parts match when needed, then combine them.
Type the full expression
Examples: 1/4 + 2/3, 2 + 3/4, 1 1/2 + 2/3, or 1/6 + 2/6 + 3/6.
Visual explanation
Notice the matching parts
These fractions already name pieces of the same size.
First addend2/1
2 wholes
Second addend1/3
Quick answer
Pull everything over one bar
In 2 + 1/3, the whole 2 becomes 6/3 — two wholes are six thirds. Then one addition runs under a single denominator: 6/3 + 1/3 = 7/3. The improper form is the requested finish; regrouping to 2 1/3 would undo the “single fraction” part.
When the fractions have unlike denominators, the common-denominator step comes first: 1/2 + 1/3 = 3/6 + 2/6 = 5/6. Same request, one extra rewrite.
The method
Four steps: convert, match, combine, simplify
Give unlike denominators a common one
In 1/2 + 1/3, rewrite both over 6: 3/6 + 2/6. The whole-number rewrite in step 1 already uses this denominator.
Combine the numerators over one bar
Add or subtract the numerators and keep the common denominator: 3/6 + 2/6 = 5/6. The result is a single fraction — one numerator, one bar, one denominator.
Simplify unless the question wants it raw
Reduce if top and bottom share a factor. Leave the answer improper when the question says "as a single fraction" — 7/3 is the finished form; 2 1/3 is the regrouped reading of it.
Worked example
Whole plus fraction: 2 + 1/3
2 + 1/3 = 6/3 + 1/3 = 7/3
The whole 2 becomes 6/3 — two wholes are six thirds. One bar now carries the entire expression: 7/3. Regrouped it reads 2 1/3, but 7/3 is the single-fraction form the question asked for.
Worked example
Two fractions with unlike denominators: 1/2 + 1/3
1/2 + 1/3 = 3/6 + 2/6 = 5/6
The common denominator 6 unites the pieces: 3 sixths plus 2 sixths is 5 sixths, already in lowest terms. One fraction, no whole-number part.
Worked example
Subtraction from a whole: 3 − 1/4
3 − 1/4 = 12/4 − 1/4 = 11/4
Three wholes are 12 quarters. Taking one away leaves 11/4 — a single improper fraction, which is exactly the form "write as a single fraction" requests.
Worked example
A mixed number in the mix: 1 1/2 + 2/5
1 1/2 + 2/5 = 3/2 + 2/5 = 15/10 + 4/10 = 19/10
The mixed number converts to the improper 3/2 first. Then both fractions meet over 10: 19/10. Regrouping would give 1 9/10, but the single fraction is complete as it stands.
Why the improper form is the point
A mixed number splits one amount across two notations — a whole column and a fraction column. That is pleasant for reading but awkward for whatever comes next: multiplying by the result, subtracting from it, or plugging it into a formula all want one numerator and one denominator. The single-fraction request is really a request for calculation-readiness.
It also standardises expressions that mix forms. In 1 1/2 + 2/5, converting the mixed number to 3/2 puts both addends in the same language, and the common denominator 10 finishes the job: 19/10. One bar, one value, ready for the next operation — that is the entire goal.
Review the mixed-to-improper conversionCommon mistakes to avoid
- Leaving the whole number outside the bar: Writing 2 + 1/3 = 2 1/3 answers a different request. "Single fraction" means the whole must enter the fraction: 6/3 + 1/3 = 7/3, one bar total.
- Multiplying the whole by the numerator instead of the denominator: Rewriting 2 for thirds gives 6/3 — two wholes are six thirds (2 × 3 on top). Writing 2/3 treats two as two thirds and loses two wholes’ worth of value.
- Regrouping into a mixed number at the end: 7/3 is the requested form; 2 1/3 is a different notation for the same value. Unless the question asks for a mixed number, the single fraction stands as the answer — improper is not wrong here.
Keep learning
Related fraction topics
Common questions
Write as a Single Fraction FAQ
Convert every whole number and mixed number into fractions, give everything a common denominator, then combine the numerators over that one denominator. For 2 + 1/3: 6/3 + 1/3 = 7/3. For 1/2 + 1/3: 3/6 + 2/6 = 5/6.