Math worksheet for practicing adding and subtracting fractions, featuring 16 problems with varying denominators.

Let's solve each of these adding and subtracting fractions problems step by step. We'll find common denominators, perform the operations, and simplify where needed.

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1. $\frac{1}{3} + \frac{2}{7}$

- LCD of 3 and 7 is 21.
- $\frac{1}{3} = \frac{7}{21},\quad \frac{2}{7} = \frac{6}{21}$
- $\frac{7}{21} + \frac{6}{21} = \frac{13}{21}$

✔ Answer: $\boxed{\frac{13}{21}}$

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2. $\frac{1}{12} + \frac{1}{3}$

- LCD of 12 and 3 is 12.
- $\frac{1}{3} = \frac{4}{12}$
- $\frac{1}{12} + \frac{4}{12} = \frac{5}{12}$

✔ Answer: $\boxed{\frac{5}{12}}$

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3. $\frac{1}{10} + \frac{2}{9}$

- LCD of 10 and 9 is 90.
- $\frac{1}{10} = \frac{9}{90},\quad \frac{2}{9} = \frac{20}{90}$
- $\frac{9}{90} + \frac{20}{90} = \frac{29}{90}$

✔ Answer: $\boxed{\frac{29}{90}}$

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4. $\frac{3}{6} - \frac{2}{7}$

- Simplify $\frac{3}{6} = \frac{1}{2}$
- LCD of 2 and 7 is 14.
- $\frac{1}{2} = \frac{7}{14},\quad \frac{2}{7} = \frac{4}{14}$
- $\frac{7}{14} - \frac{4}{14} = \frac{3}{14}$

✔ Answer: $\boxed{\frac{3}{14}}$

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5. $\frac{2}{3} + \frac{3}{16}$

- LCD of 3 and 16 is 48.
- $\frac{2}{3} = \frac{32}{48},\quad \frac{3}{16} = \frac{9}{48}$
- $\frac{32}{48} + \frac{9}{48} = \frac{41}{48}$

✔ Answer: $\boxed{\frac{41}{48}}$

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6. $\frac{1}{8} - \frac{1}{16}$

- LCD of 8 and 16 is 16.
- $\frac{1}{8} = \frac{2}{16}$
- $\frac{2}{16} - \frac{1}{16} = \frac{1}{16}$

✔ Answer: $\boxed{\frac{1}{16}}$

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7. $\frac{1}{10} + \frac{6}{5}$

- LCD of 10 and 5 is 10.
- $\frac{6}{5} = \frac{12}{10}$
- $\frac{1}{10} + \frac{12}{10} = \frac{13}{10} = 1\frac{3}{10}$

✔ Answer: $\boxed{\frac{13}{10}}$ or $\boxed{1\frac{3}{10}}$

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8. $\frac{9}{10} - \frac{1}{10}$

- Same denominator: $\frac{9 - 1}{10} = \frac{8}{10} = \frac{4}{5}$

✔ Answer: $\boxed{\frac{4}{5}}$

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9. $\frac{2}{3} - \frac{4}{9}$

- LCD of 3 and 9 is 9.
- $\frac{2}{3} = \frac{6}{9}$
- $\frac{6}{9} - \frac{4}{9} = \frac{2}{9}$

✔ Answer: $\boxed{\frac{2}{9}}$

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10. $\frac{8}{12} - \frac{8}{16}$

- Simplify: $\frac{8}{12} = \frac{2}{3},\quad \frac{8}{16} = \frac{1}{2}$
- LCD of 3 and 2 is 6.
- $\frac{2}{3} = \frac{4}{6},\quad \frac{1}{2} = \frac{3}{6}$
- $\frac{4}{6} - \frac{3}{6} = \frac{1}{6}$

✔ Answer: $\boxed{\frac{1}{6}}$

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11. $\frac{2}{6} - \frac{1}{6}$

- Same denominator: $\frac{2 - 1}{6} = \frac{1}{6}$

✔ Answer: $\boxed{\frac{1}{6}}$

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12. $\frac{1}{11} + \frac{1}{4}$

- LCD of 11 and 4 is 44.
- $\frac{1}{11} = \frac{4}{44},\quad \frac{1}{4} = \frac{11}{44}$
- $\frac{4}{44} + \frac{11}{44} = \frac{15}{44}$

✔ Answer: $\boxed{\frac{15}{44}}$

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13. $\frac{3}{6} - \frac{1}{6}$

- Same denominator: $\frac{3 - 1}{6} = \frac{2}{6} = \frac{1}{3}$

✔ Answer: $\boxed{\frac{1}{3}}$

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14. $\frac{2}{4} + \frac{2}{5}$

- Simplify: $\frac{2}{4} = \frac{1}{2}$
- LCD of 2 and 5 is 10.
- $\frac{1}{2} = \frac{5}{10},\quad \frac{2}{5} = \frac{4}{10}$
- $\frac{5}{10} + \frac{4}{10} = \frac{9}{10}$

✔ Answer: $\boxed{\frac{9}{10}}$

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15. $\frac{2}{15} - \frac{1}{10}$

- LCD of 15 and 10 is 30.
- $\frac{2}{15} = \frac{4}{30},\quad \frac{1}{10} = \frac{3}{30}$
- $\frac{4}{30} - \frac{3}{30} = \frac{1}{30}$

✔ Answer: $\boxed{\frac{1}{30}}$

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16. $\frac{1}{11} + \frac{5}{7}$

- LCD of 11 and 7 is 77.
- $\frac{1}{11} = \frac{7}{77},\quad \frac{5}{7} = \frac{55}{77}$
- $\frac{7}{77} + \frac{55}{77} = \frac{62}{77}$

✔ Answer: $\boxed{\frac{62}{77}}$

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✔ Final Answers:

| Problem | Answer |
|--------|--------|
| 1 | $\frac{13}{21}$ |
| 2 | $\frac{5}{12}$ |
| 3 | $\frac{29}{90}$ |
| 4 | $\frac{3}{14}$ |
| 5 | $\frac{41}{48}$ |
| 6 | $\frac{1}{16}$ |
| 7 | $\frac{13}{10}$ or $1\frac{3}{10}$ |
| 8 | $\frac{4}{5}$ |
| 9 | $\frac{2}{9}$ |
| 10 | $\frac{1}{6}$ |
| 11 | $\frac{1}{6}$ |
| 12 | $\frac{15}{44}$ |
| 13 | $\frac{1}{3}$ |
| 14 | $\frac{9}{10}$ |
| 15 | $\frac{1}{30}$ |
| 16 | $\frac{62}{77}$ |

Let me know if you'd like a printable version or explanation for any specific problem!