Math Buddyv1.0

Calculator with fractions, step by step

Type or scan a fraction problem. MathBuddy finds the common denominator, simplifies and shows each step.

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What this page covers

  • Adding and subtracting fractions with different denominators, using the least common denominator.
  • Multiplying and dividing fractions, including whole numbers written over 1.
  • Problems that mix several operations and brackets, worked in the usual order of operations.
  • Not covered here: mixed numbers such as 2 1/2 (use Mixed number calculator) and fractions with letters in them (use Algebra calculator with steps).

How to enter the problem

  • Type it with a slash, such as 3/4 + 5/6, or use the fraction key on the math keyboard.
  • Scan it. Fit the one problem in the frame.
  • Choose a photo. Several problems in one photo are solved as a list.
  • Then tap Solve.

Worked examples

Example 1

Problem

Subtract: 23−14\displaystyle \frac{2}{3} - \frac{1}{4}.

Answer

Verified

The answer is

512\frac{5}{12}

Explanation

  1. Find the least common denominator
    The smallest number that both 3 and 4 divide into is 1212.
  2. Rewrite each fraction over 12
    23=812\frac{2}{3} = \frac{8}{12} and 14=312\frac{1}{4} = \frac{3}{12}.
  3. Subtract the numerators
    812−312=512\frac{8}{12} - \frac{3}{12} = \frac{5}{12}. The denominator stays 1212.
  4. Check lowest terms
    55 and 1212 have no common factor other than 11, so the fraction is already reduced.

Example 2

Problem

Divide: 58÷1516\displaystyle \frac{5}{8} \div \frac{15}{16}.

Answer

Verified

The answer is

23\frac{2}{3}

Explanation

  1. Multiply by the reciprocal
    Dividing by 1516\frac{15}{16} is the same as multiplying by 1615\frac{16}{15}: 58⋅1615\frac{5}{8} \cdot \frac{16}{15}.
  2. Cancel common factors first
    55 and 1515 share a factor 55; 88 and 1616 share a factor 88. This leaves 11⋅23\frac{1}{1} \cdot \frac{2}{3}.
  3. Multiply
    1⋅21⋅3=23\frac{1 \cdot 2}{1 \cdot 3} = \frac{2}{3}

Example 3

Problem

Evaluate: 34⋅29+16\displaystyle \frac{3}{4} \cdot \frac{2}{9} + \frac{1}{6}.

Answer

Verified

The answer is

13\frac{1}{3}

Explanation

  1. Multiply before adding
    34⋅29=636\frac{3}{4} \cdot \frac{2}{9} = \frac{6}{36}
  2. Reduce the product
    636=16\frac{6}{36} = \frac{1}{6}, dividing top and bottom by 66.
  3. Add the fractions
    Both have denominator 66
    16+16=26\frac{1}{6} + \frac{1}{6} = \frac{2}{6}
  4. Reduce to lowest terms
    26=13\frac{2}{6} = \frac{1}{3}

Common mistakes

  • Adding tops and bottoms straight across. 34+56\frac{3}{4} + \frac{5}{6} is not 810\frac{8}{10}; the denominators have to match first.
  • Flipping the wrong fraction when dividing. Only the second fraction, the one you divide by, is turned upside down.
  • Looking for a common denominator when multiplying. For a product, multiply the numerators together and the denominators together.
  • Stopping before lowest terms, for example leaving 636\frac{6}{36} where 16\frac{1}{6} is expected.

Checks, assumptions and limits

  • Check with decimals. For the runnable example, 1912≈1.583\frac{19}{12} \approx 1.583, and 0.75+0.833≈1.5830.75 + 0.833 \approx 1.583.
  • A denominator can never be 0, and dividing by a fraction equal to 0 has no answer.
  • An answer larger than 1 can be written as an improper fraction such as 1912\frac{19}{12} or as a mixed number, 17121\tfrac{7}{12}. Both are the same number.
  • MathBuddy can make mistakes. Double check important steps.

Related tasks

Frequently asked questions

Find the smallest number that both denominators divide into. For 4 and 6 it is 12. Then multiply the top and bottom of each fraction by whatever turns its denominator into 12.

Dividing by a number is the same as multiplying by its reciprocal. 15/16 times 16/15 is 1, so multiplying by 16/15 undoes a multiplication by 15/16.

Yes. Choose a photo and several problems in one photo are solved as a list. Use the camera on one problem to solve just that one.

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