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 informations.

The result:

12 9/10 - 8 3/5 = 43/10 = 4 3/10 = 4.3

The spelled result in words is forty-three tenths (or four and three tenths).

How do we solve fractions step by step?

  1. Conversion a mixed number 12 9/10 to a improper fraction: 12 9/10 = 12 9/10 = 12 · 10 + 9/10 = 120 + 9/10 = 129/10

    To find a new numerator:
    a) Multiply the whole number 12 by the denominator 10. Whole number 12 equally 12 * 10/10 = 120/10
    b) Add the answer from the previous step 120 to the numerator 9. New numerator is 120 + 9 = 129
    c) Write a previous answer (new numerator 129) over the denominator 10.

    Twelve and nine tenths is one hundred twenty-nine tenths.
  2. Conversion a mixed number 8 3/5 to a improper fraction: 8 3/5 = 8 3/5 = 8 · 5 + 3/5 = 40 + 3/5 = 43/5

    To find a new numerator:
    a) Multiply the whole number 8 by the denominator 5. Whole number 8 equally 8 * 5/5 = 40/5
    b) Add the answer from the previous step 40 to the numerator 3. New numerator is 40 + 3 = 43
    c) Write a previous answer (new numerator 43) over the denominator 5.

    Eight and three fifths is forty-three fifths.
  3. Subtract: 129/10 - 43/5 = 129/10 - 43 · 2/5 · 2 = 129/10 - 86/10 = 129 - 86/10 = 43/10
    It is suitable to adjust both fractions to a common (equal, identical) denominator for adding, subtracting, and comparing fractions. The common denominator you can calculate as the least common multiple of both denominators - LCM(10, 5) = 10. It is enough to find the common denominator (not necessarily the lowest) by multiplying the denominators: 10 × 5 = 50. In the following intermediate step, it cannot further simplify the fraction result by canceling.
    In other words - one hundred twenty-nine tenths minus forty-three fifths is forty-three tenths.

Rules for expressions with fractions:

Fractions - use a forward slash to divide the numerator by 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 integer and
fraction and use a forward slash to input fractions i.e., 1 2/3 . An example of a negative mixed fraction: -5 1/2.
Because slash is both sign for fraction line and division, use a colon (:) as the operator of division fractions i.e., 1/2 : 1/3.
Decimals (decimal numbers) enter with a decimal point . 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 of operations are:
PEMDAS - Parentheses, Exponents, Multiplication, Division, Addition, Subtraction.
BEDMAS - Brackets, Exponents, Division, Multiplication, Addition, Subtraction
BODMAS - Brackets, Of or Order, Division, Multiplication, Addition, Subtraction.
GEMDAS - Grouping Symbols - brackets (){}, Exponents, Multiplication, Division, Addition, Subtraction.
MDAS - Multiplication and Division have the same precedence over Addition and Subtraction. The MDAS rule is the order of operations part of the PEMDAS rule.
Be careful; always do multiplication and division before addition and subtraction. Some operators (+ and -) and (* and /) have the same priority and must be evaluated from left to right.


Last Modified: July 13, 2024