Fraction calculator



This fraction calculator performs all fraction operations - addition, subtraction, multiplication, division and evaluates expressions with fractions. It also shows detailed step-by-step information.

The result:

-5/12 - 5 - 7/18 = -209/36 = -5 29/36 ≅ -5.8055556

The result spelled out in words is minus two hundred nine thirty-sixths (or minus five and twenty-nine thirty-sixths).

How do we solve fractions step by step?

  1. Unary minus: -5/12 = -5/12
  2. Subtract: the result of step No. 1 - 5 = -5/12 - 5 = -5/12 - 5/1 = -5/12 - 5 · 12/1 · 12 = -5/12 - 60/12 = -5 - 60/12 = -65/12
    The second operand is an integer. It is equivalent to the fraction 5/1. It is suitable to adjust both fractions to a common (equal) denominator for subtracting fractions. The common denominator you can calculate as the least common multiple of both denominators - LCM(12, 1) = 12. It is enough to find the common denominator (not necessarily the lowest) by multiplying the denominators: 12 × 1 = 12. In the following intermediate step, it cannot further simplify the fraction result by canceling.
    In other words, minus five twelfths minus five equals minus sixty-five twelfths.
  3. Subtract: the result of step No. 2 - 7/18 = -65/12 - 7/18 = -65 · 3/12 · 3 - 7 · 2/18 · 2 = -195/36 - 14/36 = -195 - 14/36 = -209/36
    It is suitable to adjust both fractions to a common (equal) denominator for subtracting fractions. The common denominator you can calculate as the least common multiple of both denominators - LCM(12, 18) = 36. It is enough to find the common denominator (not necessarily the lowest) by multiplying the denominators: 12 × 18 = 216. In the following intermediate step, it cannot further simplify the fraction result by canceling.
    In other words, minus sixty-five twelfths minus seven eighteenths equals minus two hundred nine thirty-sixths.

Rules for expressions with fractions:

Fractions - write a forward slash to separate the numerator and the denominator, i.e., for five-hundredths, enter 5/100. If you use mixed numbers, leave a space between the whole and fraction parts.

Mixed numerals (mixed numbers or fractions) - keep one space between the whole part and fraction and use a forward slash to input fraction i.e., 1 2/3 . A negative mixed fraction write for example as -5 1/2.
A slash is both a sign for fraction line and division, use a colon (:) for division fractions i.e., 1/2 : 1/3.
Decimals (decimal numbers) enter with a decimal dot . and they are automatically converted to fractions - i.e. 1.45.


Math Symbols


SymbolSymbol nameSymbol MeaningExample
+plus signaddition 1/2 + 1/3
-minus signsubtraction 1 1/2 - 2/3
*asteriskmultiplication 2/3 * 3/4
×times signmultiplication 2/3 × 5/6
:division signdivision 1/2 : 3
/division slashdivision 1/3 / 5
:coloncomplex fraction 1/2 : 1/3
^caretexponentiation / power 1/4^3
()parenthesescalculate expression inside first-3/5 - (-1/4)


The calculator follows well-known rules for the order of operations. The most common mnemonics for remembering this order are:
  • PEMDAS: Parentheses, Exponents, Multiplication, Division, Addition, Subtraction.
  • BEDMAS: Brackets, Exponents, Division, Multiplication, Addition, Subtraction.
  • BODMAS: Brackets, Order (or "Of"), Division, Multiplication, Addition, Subtraction.
  • GEMDAS: Grouping symbols (brackets: (){}), Exponents, Multiplication, Division, Addition, Subtraction.
  • MDAS: Multiplication and Division (same precedence), Addition and Subtraction (same precedence). MDAS is a subset of PEMDAS.
Important Notes:
1. Multiplication/Division vs. Addition/Subtraction: Always perform multiplication and division *before* addition and subtraction.
2. Left-to-Right Rule: Operators with the same precedence (e.g., + and -, or * and /) must be evaluated from left to right.

Last Modified: August 28, 2025