Content

• To step
• Method 1 of 2: Subtract fractions from whole numbers
• Necessities

Subtracting fractions from whole numbers is not as difficult as it may seem. The two main ways to do this are: converting the whole number to a fraction, or subtracting 1 from the whole number and converting that 1 to a fraction with the same denominator as the fraction you are subtracting from it. Once you have fractions with the same denominator, you can start with the minus sum. With either method, you will be able to quickly and easily subtract fractions from whole numbers.

To step

Method 1 of 2: Subtract fractions from whole numbers

1. Convert the whole number to a fraction. You do this by giving the whole number a denominator of 1.
   • Example: ${ displaystyle 8 - { frac {4} {5}}}$Convert two fractions with like denominators. The denominator of the original fraction is also the least common divisor (LCD) of these two fractions. Multiply the numerator and denominator of the whole number that you converted into a fraction by this number, so that both fractions have the same denominator.
     • ${ displaystyle { frac {8} {1}} - { frac {4} {5}}}$Subtract the counters. Now that both fractions have the same denominator, you can subtract the denominators like you would with a regular subtraction sum:
       • ${ displaystyle { frac {40} {5}} - { frac {4} {5}}}$Convert to a mixed number (optional). If your answer is an improper fraction, you may have to rewrite it as a mixed number:
         • Example: Rewrite ${ displaystyle { frac {36} {5}}}$Try this for larger integers. Have you seen how you can convert a whole number to a fraction using the above method and then eventually convert it back to a mixed number? With this method, you can skip part of this method so that the fraction is solved with small numbers.
         • Convert an improper fraction to a mixed number. Skip this step if your fraction is not improper. (For an improper fraction, the numerator is greater than the denominator).
           • Example: ${ displaystyle 11 - { frac {4} {3}}}$Divide the whole number into 1 and another integer. For example, rewrite 5 as 4 + 1, or 22 as 21 + 1.
             • ${ displaystyle 10 - { frac {1} {3}}}$Convert the 1 to a fraction. At this point, we use the above method to solve that part of the problem in the form of a "1 - (fraction)". The other integer remains unchanged for the rest of the solutions.
               • ${ displaystyle = 9 + 1 - { frac {1} {3}}}$Multiply to give both fractions the same denominator. As indicated above, multiply the numerator and denominator by the same number so that the converted fraction has the same denominator as the original.
                 • ${ displaystyle = 9 + { frac {1 * 3} {1 * 3}} - { frac {1} {3}}}$Subtract both fractions. Subtract the numerators of both fractions to solve the fraction part of the equation.
                   • ${ displaystyle = 9 + { frac {3-1} {3}}}$
                   • ${ displaystyle = 9 + { frac {2} {3}}}$
                   • ${ displaystyle = 9 { frac {2} {3}}}$

Necessities

• Pencil
• Paper