Fractions Operations Rules and Practice
This worksheet is a short reminder of important fraction skills. Read each rule, study the example, and then try the practice sets.
1 Mixed fractions and improper fractions
A mixed fraction has a whole number and a fraction, such as \(2\frac{1}{3}\).
An improper fraction has a numerator that is equal to or greater than its denominator, such as \(\frac{7}{3}\).
1.1 Mixed fraction to improper fraction
- Multiply the whole number by the denominator.
- Add the numerator.
- Keep the same denominator.
Example: \(2\frac{1}{3}=\frac{2\times3+1}{3}=\frac{7}{3}\).
1.2 Improper fraction to mixed fraction
- Divide the numerator by the denominator.
- The answer from the division is the whole number.
- The remainder becomes the new numerator.
- Keep the same denominator.
Example: \(\frac{11}{4}=2\frac{3}{4}\) because \(11\) divided by \(4\) gives \(2\) with a remainder of \(3\).
2 Adding fractions
2.1 Same denominators
Keep the denominator, add the numerators, and simplify if possible.
Example: \(\frac{2}{7}+\frac{3}{7}=\frac{5}{7}\).
2.2 Different denominators
- Multiply the numerator and denominator of the first fraction by the denominator of the second fraction.
- Multiply the numerator and denominator of the second fraction by the denominator of the first fraction.
- Add the new numerators and keep the new denominator.
- Simplify the answer.
Example:
\[ \frac{1}{2}+\frac{1}{3}=\frac{1\times3}{2\times3}+\frac{1\times2}{3\times2}=\frac{3}{6}+\frac{2}{6}=\frac{5}{6} \]
2.3 Adding mixed fractions
- Change each mixed fraction into an improper fraction.
- Add the improper fractions.
- Change the answer back into a mixed fraction if needed.
Example: \(1\frac{2}{5}+2\frac{4}{5}=\frac{7}{5}+\frac{14}{5}=\frac{21}{5}=4\frac{1}{5}\).
3 Subtracting fractions
3.1 Same denominators
Keep the denominator, subtract the numerators, and simplify if possible.
Example: \(\frac{6}{9}-\frac{2}{9}=\frac{4}{9}\).
3.2 Different denominators
- Multiply the numerator and denominator of the first fraction by the denominator of the second fraction.
- Multiply the numerator and denominator of the second fraction by the denominator of the first fraction.
- Subtract the new numerators and keep the new denominator.
- Simplify the answer.
Example:
\[ \frac{3}{4}-\frac{1}{6}=\frac{3\times6}{4\times6}-\frac{1\times4}{6\times4}=\frac{18}{24}-\frac{4}{24}=\frac{14}{24}=\frac{7}{12} \]
3.3 Subtracting mixed fractions
- Change each mixed fraction into an improper fraction.
- Subtract the improper fractions.
- Change the answer back into a mixed fraction if needed.
Example: \(3\frac{1}{4}-1\frac{3}{4}=\frac{13}{4}-\frac{7}{4}=\frac{6}{4}=1\frac{1}{2}\).
4 Multiplying fractions
- Multiply the numerators.
- Multiply the denominators.
- Simplify the answer.
Example: \(\frac{2}{3}\times\frac{4}{5}=\frac{8}{15}\).
For a mixed fraction, first change it into an improper fraction. Example: \(1\frac{1}{2}\times\frac{2}{3}=\frac{3}{2}\times\frac{2}{3}=1\).
5 Dividing fractions
- Keep the first fraction.
- Change division to multiplication.
- Turn the second fraction upside down.
- Multiply and simplify.
Example: \(\frac{3}{4}\div\frac{2}{5}=\frac{3}{4}\times\frac{5}{2}=\frac{15}{8}=1\frac{7}{8}\).
For division by a whole number, write the whole number over \(1\). Example: \(\frac{5}{6}\div2=\frac{5}{6}\times\frac{1}{2}=\frac{5}{12}\).
6 Helpful reminders
- The denominator tells the number of the equal parts.
- The numerator tells how many parts we have.
- For addition and subtraction, make the denominators the same by multiplying each fraction by the other fraction’s denominator.
- For multiplication, just multiply the numerators and denominators directly.
- For division, multiply by the reciprocal of the second fraction.
- Always simplify the final answer when possible.
- Check whether an improper answer should be written as a mixed fraction.
7 Practice set 1
- Change \(3\frac{2}{5}\) into an improper fraction.
- Change \(\frac{17}{4}\) into a mixed fraction.
- \(\frac{3}{8}+\frac{2}{8}\)
- \(\frac{1}{3}+\frac{1}{6}\)
- \(\frac{7}{10}-\frac{3}{10}\)
- \(\frac{5}{6}-\frac{1}{4}\)
- \(\frac{2}{5}\times\frac{3}{4}\)
- \(1\frac{1}{2}\times\frac{2}{3}\)
- \(\frac{3}{7}\div\frac{2}{5}\)
- \(2\frac{1}{4}\div\frac{3}{4}\)
8 Practice set 2
- Change \(4\frac{3}{7}\) into an improper fraction.
- Change \(\frac{23}{6}\) into a mixed fraction.
- \(2\frac{1}{5}+1\frac{3}{5}\)
- \(\frac{5}{8}+\frac{1}{4}\)
- \(4\frac{1}{3}-2\frac{2}{3}\)
- \(\frac{7}{9}-\frac{1}{6}\)
- \(\frac{3}{10}\times\frac{5}{6}\)
- \(2\frac{2}{3}\times\frac{3}{4}\)
- \(\frac{5}{8}\div\frac{10}{11}\)
- \(3\frac{1}{2}\div\frac{7}{8}\)
9 Practice set 3
- Change \(5\frac{5}{9}\) into an improper fraction.
- Change \(\frac{31}{5}\) into a mixed fraction.
- \(3\frac{3}{4}+2\frac{5}{8}\)
- \(\frac{7}{12}+\frac{5}{18}\)
- \(6\frac{1}{5}-3\frac{4}{5}\)
- \(\frac{11}{12}-\frac{2}{9}\)
- \(\frac{4}{7}\times\frac{14}{15}\)
- \(1\frac{3}{5}\times2\frac{1}{2}\)
- \(\frac{7}{9}\div\frac{14}{15}\)
- \(4\frac{1}{2}\div1\frac{1}{8}\)