Question 1: Calculate: \( \frac{3}{7} - \frac{2}{7} \)

Answer: 1/7

Question 2: Calculate: \( \frac{5}{9} - \frac{2}{9} \)

Answer: 3/9 or 1/3

Question 3: A baker uses \( \frac{4}{5} \) of a kilogram of flour. He uses \( \frac{1}{5} \) of a kilogram in one recipe. How much flour is left?

Answer: 3/5

Question 4: Subtract: \( \frac{7}{10} - \frac{3}{10} \)

Answer: 4/10 or 2/5

Question 5: If you subtract \( \frac{2}{8} \) from \( \frac{5}{8} \), what is the result?

Answer: 3/8

Question 6: Solve: \( \frac{6}{11} - \frac{4}{11} \)

Answer: 2/11

Question 7: A student has \( \frac{7}{12} \) of a chocolate bar. She eats \( \frac{2}{12} \). How much remains?

Answer: 5/12

Question 8: Calculate: \( \frac{9}{15} - \frac{4}{15} \)

Answer: 5/15 or 1/3

Question 9: Subtract the proper fractions: \( \frac{8}{20} - \frac{3}{20} \)

Answer: 5/20 or 1/4

Question 10: Identify and correct the mistake: \( \frac{3}{8} - \frac{3}{8} = \frac{0}{8} = 0 \).

Answer: Correct: \( \frac{3}{8} - \frac{3}{8} = 0 \). The mistake is in saying \( \frac{0}{8} = 0 \); it's correct, but clarify that the result is zero.

Question 11: Challenge: Subtract \( \frac{9}{14} \) and \( \frac{5}{14} \). Then, explain why the difference is a proper fraction.

Answer: 4/14 or 2/7; because the difference is less than 1, it's a proper fraction.