Examples · Fractions
Fraction Examples: 10 Worked Problems With Answers
Ten problems, worked in full. They are ordered so each one adds exactly one new difficulty to the last.
Adding and subtracting
The first three fraction examples build up the one difficulty that matters here: denominators that do not match.
- 3⁄8 + 2⁄8the parts are already the same size
- 5⁄8add the numerators, keep the denominator
- 7⁄8 − 1⁄4quarters and eighths
- 7⁄8 − 2⁄84 divides 8, so only the second needs rewriting
- 5⁄8subtract the numerators
- 2⁄3 + 1⁄4thirds and quarters
- 8⁄12 + 3⁄1212 is the least common denominator
- 11⁄12add, and it is already in lowest terms
Multiplying and dividing
No common denominator is needed here, but cancelling early saves work.
- 3⁄4 × 2⁄5multiply across
- 6⁄20numerators together, denominators together
- 3⁄10divide top and bottom by 2
- 3⁄4 × 8⁄93 and 9 share 3; 4 and 8 share 4
- 1⁄1 × 2⁄3cancel before multiplying
- 2⁄3no simplification left to do
- 5⁄6 ÷ 10⁄3how many tenths-of-three fit into five sixths?
- 5⁄6 × 3⁄10multiply by the reciprocal
- 15⁄60 = 1⁄4multiply across, then simplify
Mixed numbers
Convert to improper fractions first. It is more writing, but there is no carrying step to forget.
- 1 ½ + 2 ⅓the sum
- 3⁄2 + 7⁄3convert both to improper fractions
- 9⁄6 + 14⁄6common denominator 6
- 23⁄6 = 3 ⅚add, then convert back
- 3 ¼ − 1 ½the quarter is smaller than the half
- 13⁄4 − 3⁄2improper form avoids borrowing entirely
- 13⁄4 − 6⁄4common denominator 4
- 7⁄4 = 1 ¾subtract, then convert back
Simplifying and comparing
Two more worked examples, covering the operations that are not addition, subtraction, multiplying fractions or dividing fractions but turn up in almost every question anyway.
- 36⁄48both are divisible by 12
- (36 ÷ 12)⁄(48 ÷ 12)divide top and bottom by the greatest common factor
- 3⁄4no shared factor remains
- 3⁄5 or 5⁄8 — which is larger?the question
- 24⁄40 and 25⁄40rewrite both over 40
- 5⁄8 is larger25 fortieths beats 24 fortieths
If you only need to know which is bigger and not by how much, cross-multiply instead: 3 × 8 = 24 against 5 × 5 = 25. The larger product sits above the larger fraction.
Word problems
The arithmetic here is easy. Deciding which operation the words describe is the actual task, and 'of' almost always signals multiplication.
- ⅔ of 3⁄4 of a tank'of' means multiply
- 2⁄3 × 3⁄4set it up
- 6⁄12 = 1⁄2half a tank
- 3⁄4 kg shared into portions of 1⁄8 kghow many portions fit?
- 3⁄4 ÷ 1⁄8'how many fit into' means divide
- 3⁄4 × 8⁄1 = 6six portions
Questions about fraction examples
What is the hardest part of fraction problems?
For arithmetic, finding the common denominator. For word problems, deciding which operation is being described — most lost marks come from the setup, not the sums.
Should I always convert mixed numbers to improper fractions?
For adding and subtracting, yes — it removes the borrowing step. For multiplying and dividing it is not optional, because the methods only work on improper form.
How do I check a fraction answer?
Estimate first. 2/3 + 1/4 must be a little under 1, so an answer of 11/12 is plausible and an answer of 3/7 is not. This catches wrong methods, not just wrong arithmetic.
Does 'of' always mean multiply?
In fraction problems, almost always. Two thirds of three quarters is 2/3 × 3/4.