Math worksheet for practicing addition and subtraction of fractions with unlike denominators.
A worksheet titled "Unlike Denominators" with ten math problems involving addition and subtraction of fractions with different denominators, including spaces for answers.
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Step-by-step solution for: Adding and Subtracting Unlike Denominators worksheet
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Show Answer Key & Explanations
Step-by-step solution for: Adding and Subtracting Unlike Denominators worksheet
Let's solve each of these fraction problems step by step. The key idea when adding or subtracting fractions with unlike denominators is to:
1. Find the Least Common Denominator (LCD).
2. Convert each fraction to an equivalent fraction with the LCD.
3. Add or subtract the numerators.
4. Simplify the result if needed.
---
$$
\frac{2}{3} + \frac{1}{2}
$$
- LCD of 3 and 2 is 6
- Convert:
$$
\frac{2}{3} = \frac{4}{6},\quad \frac{1}{2} = \frac{3}{6}
$$
- Add:
$$
\frac{4}{6} + \frac{3}{6} = \frac{7}{6}
$$
- Answer: $\boxed{\frac{7}{6}}$ or $1\frac{1}{6}$
---
$$
\frac{2}{5} + \frac{1}{10}
$$
- LCD of 5 and 10 is 10
- Convert:
$$
\frac{2}{5} = \frac{4}{10},\quad \frac{1}{10} = \frac{1}{10}
$$
- Add:
$$
\frac{4}{10} + \frac{1}{10} = \frac{5}{10} = \frac{1}{2}
$$
- Answer: $\boxed{\frac{1}{2}}$
---
$$
\frac{1}{5} + \frac{2}{4}
$$
- Simplify $\frac{2}{4} = \frac{1}{2}$
- Now: $\frac{1}{5} + \frac{1}{2}$
- LCD of 5 and 2 is 10
- Convert:
$$
\frac{1}{5} = \frac{2}{10},\quad \frac{1}{2} = \frac{5}{10}
$$
- Add:
$$
\frac{2}{10} + \frac{5}{10} = \frac{7}{10}
$$
- Answer: $\boxed{\frac{7}{10}}$
---
$$
\frac{3}{5} + \frac{3}{8}
$$
- LCD of 5 and 8 is 40
- Convert:
$$
\frac{3}{5} = \frac{24}{40},\quad \frac{3}{8} = \frac{15}{40}
$$
- Add:
$$
\frac{24}{40} + \frac{15}{40} = \frac{39}{40}
$$
- Answer: $\boxed{\frac{39}{40}}$
---
$$
\frac{2}{7} + \frac{1}{4}
$$
- LCD of 7 and 4 is 28
- Convert:
$$
\frac{2}{7} = \frac{8}{28},\quad \frac{1}{4} = \frac{7}{28}
$$
- Add:
$$
\frac{8}{28} + \frac{7}{28} = \frac{15}{28}
$$
- Answer: $\boxed{\frac{15}{28}}$
---
$$
\frac{3}{5} - \frac{3}{10}
$$
- LCD of 5 and 10 is 10
- Convert:
$$
\frac{3}{5} = \frac{6}{10},\quad \frac{3}{10} = \frac{3}{10}
$$
- Subtract:
$$
\frac{6}{10} - \frac{3}{10} = \frac{3}{10}
$$
- Answer: $\boxed{\frac{3}{10}}$
---
$$
\frac{4}{6} - \frac{1}{12}
$$
- Simplify $\frac{4}{6} = \frac{2}{3}$
- Now: $\frac{2}{3} - \frac{1}{12}$
- LCD of 3 and 12 is 12
- Convert:
$$
\frac{2}{3} = \frac{8}{12},\quad \frac{1}{12} = \frac{1}{12}
$$
- Subtract:
$$
\frac{8}{12} - \frac{1}{12} = \frac{7}{12}
$$
- Answer: $\boxed{\frac{7}{12}}$
---
$$
\frac{4}{6} - \frac{1}{2}
$$
- Simplify $\frac{4}{6} = \frac{2}{3}$
- Now: $\frac{2}{3} - \frac{1}{2}$
- LCD of 3 and 2 is 6
- Convert:
$$
\frac{2}{3} = \frac{4}{6},\quad \frac{1}{2} = \frac{3}{6}
$$
- Subtract:
$$
\frac{4}{6} - \frac{3}{6} = \frac{1}{6}
$$
- Answer: $\boxed{\frac{1}{6}}$
---
$$
\frac{3}{4} - \frac{1}{3}
$$
- LCD of 4 and 3 is 12
- Convert:
$$
\frac{3}{4} = \frac{9}{12},\quad \frac{1}{3} = \frac{4}{12}
$$
- Subtract:
$$
\frac{9}{12} - \frac{4}{12} = \frac{5}{12}
$$
- Answer: $\boxed{\frac{5}{12}}$
---
$$
\frac{7}{8} - \frac{3}{4}
$$
- LCD of 8 and 4 is 8
- Convert:
$$
\frac{3}{4} = \frac{6}{8}
$$
- Subtract:
$$
\frac{7}{8} - \frac{6}{8} = \frac{1}{8}
$$
- Answer: $\boxed{\frac{1}{8}}$
---
| Problem | Answer |
|--------|----------------|
| 1 | $\frac{7}{6}$ |
| 2 | $\frac{1}{2}$ |
| 3 | $\frac{7}{10}$ |
| 4 | $\frac{39}{40}$ |
| 5 | $\frac{15}{28}$ |
| 6 | $\frac{3}{10}$ |
| 7 | $\frac{7}{12}$ |
| 8 | $\frac{1}{6}$ |
| 9 | $\frac{5}{12}$ |
| 10 | $\frac{1}{8}$ |
Let me know if you'd like these as mixed numbers or visual representations!
1. Find the Least Common Denominator (LCD).
2. Convert each fraction to an equivalent fraction with the LCD.
3. Add or subtract the numerators.
4. Simplify the result if needed.
---
Problem 1:
$$
\frac{2}{3} + \frac{1}{2}
$$
- LCD of 3 and 2 is 6
- Convert:
$$
\frac{2}{3} = \frac{4}{6},\quad \frac{1}{2} = \frac{3}{6}
$$
- Add:
$$
\frac{4}{6} + \frac{3}{6} = \frac{7}{6}
$$
- Answer: $\boxed{\frac{7}{6}}$ or $1\frac{1}{6}$
---
Problem 2:
$$
\frac{2}{5} + \frac{1}{10}
$$
- LCD of 5 and 10 is 10
- Convert:
$$
\frac{2}{5} = \frac{4}{10},\quad \frac{1}{10} = \frac{1}{10}
$$
- Add:
$$
\frac{4}{10} + \frac{1}{10} = \frac{5}{10} = \frac{1}{2}
$$
- Answer: $\boxed{\frac{1}{2}}$
---
Problem 3:
$$
\frac{1}{5} + \frac{2}{4}
$$
- Simplify $\frac{2}{4} = \frac{1}{2}$
- Now: $\frac{1}{5} + \frac{1}{2}$
- LCD of 5 and 2 is 10
- Convert:
$$
\frac{1}{5} = \frac{2}{10},\quad \frac{1}{2} = \frac{5}{10}
$$
- Add:
$$
\frac{2}{10} + \frac{5}{10} = \frac{7}{10}
$$
- Answer: $\boxed{\frac{7}{10}}$
---
Problem 4:
$$
\frac{3}{5} + \frac{3}{8}
$$
- LCD of 5 and 8 is 40
- Convert:
$$
\frac{3}{5} = \frac{24}{40},\quad \frac{3}{8} = \frac{15}{40}
$$
- Add:
$$
\frac{24}{40} + \frac{15}{40} = \frac{39}{40}
$$
- Answer: $\boxed{\frac{39}{40}}$
---
Problem 5:
$$
\frac{2}{7} + \frac{1}{4}
$$
- LCD of 7 and 4 is 28
- Convert:
$$
\frac{2}{7} = \frac{8}{28},\quad \frac{1}{4} = \frac{7}{28}
$$
- Add:
$$
\frac{8}{28} + \frac{7}{28} = \frac{15}{28}
$$
- Answer: $\boxed{\frac{15}{28}}$
---
Problem 6:
$$
\frac{3}{5} - \frac{3}{10}
$$
- LCD of 5 and 10 is 10
- Convert:
$$
\frac{3}{5} = \frac{6}{10},\quad \frac{3}{10} = \frac{3}{10}
$$
- Subtract:
$$
\frac{6}{10} - \frac{3}{10} = \frac{3}{10}
$$
- Answer: $\boxed{\frac{3}{10}}$
---
Problem 7:
$$
\frac{4}{6} - \frac{1}{12}
$$
- Simplify $\frac{4}{6} = \frac{2}{3}$
- Now: $\frac{2}{3} - \frac{1}{12}$
- LCD of 3 and 12 is 12
- Convert:
$$
\frac{2}{3} = \frac{8}{12},\quad \frac{1}{12} = \frac{1}{12}
$$
- Subtract:
$$
\frac{8}{12} - \frac{1}{12} = \frac{7}{12}
$$
- Answer: $\boxed{\frac{7}{12}}$
---
Problem 8:
$$
\frac{4}{6} - \frac{1}{2}
$$
- Simplify $\frac{4}{6} = \frac{2}{3}$
- Now: $\frac{2}{3} - \frac{1}{2}$
- LCD of 3 and 2 is 6
- Convert:
$$
\frac{2}{3} = \frac{4}{6},\quad \frac{1}{2} = \frac{3}{6}
$$
- Subtract:
$$
\frac{4}{6} - \frac{3}{6} = \frac{1}{6}
$$
- Answer: $\boxed{\frac{1}{6}}$
---
Problem 9:
$$
\frac{3}{4} - \frac{1}{3}
$$
- LCD of 4 and 3 is 12
- Convert:
$$
\frac{3}{4} = \frac{9}{12},\quad \frac{1}{3} = \frac{4}{12}
$$
- Subtract:
$$
\frac{9}{12} - \frac{4}{12} = \frac{5}{12}
$$
- Answer: $\boxed{\frac{5}{12}}$
---
Problem 10:
$$
\frac{7}{8} - \frac{3}{4}
$$
- LCD of 8 and 4 is 8
- Convert:
$$
\frac{3}{4} = \frac{6}{8}
$$
- Subtract:
$$
\frac{7}{8} - \frac{6}{8} = \frac{1}{8}
$$
- Answer: $\boxed{\frac{1}{8}}$
---
✔ Final Answers:
| Problem | Answer |
|--------|----------------|
| 1 | $\frac{7}{6}$ |
| 2 | $\frac{1}{2}$ |
| 3 | $\frac{7}{10}$ |
| 4 | $\frac{39}{40}$ |
| 5 | $\frac{15}{28}$ |
| 6 | $\frac{3}{10}$ |
| 7 | $\frac{7}{12}$ |
| 8 | $\frac{1}{6}$ |
| 9 | $\frac{5}{12}$ |
| 10 | $\frac{1}{8}$ |
Let me know if you'd like these as mixed numbers or visual representations!
Parent Tip: Review the logic above to help your child master the concept of adding fractions unlike denominators worksheet answer keys.