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 student subtracts \( \frac{4}{8} - \frac{2}{8} \) and gets \( \frac{2}{8} \). Is this correct? Explain your answer.

Answer: Yes, because subtracting numerators over the same denominator gives \( \frac{2}{8} \).

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

Answer: 4/10 or 2/5

Question 5: Identify the mistake: A student writes \( \frac{3}{7} - \frac{4}{7} = \frac{1}{7} \). Is the answer correct? If not, correct the mistake.

Answer: No, \( \frac{3}{7} - \frac{4}{7} = -\frac{1}{7} \). The mistake was subtracting larger numerator from smaller, resulting in a negative value.

Question 6: Simplify: \( \frac{6}{9} - \frac{2}{9} \).

Answer: 4/9

Question 7: A recipe calls for \( \frac{2}{5} \) of a cup of sugar. If you want to make half the amount, how much sugar is needed? Subtract \( \frac{1}{5} \) from \( \frac{2}{5} \).

Answer: You need \( \frac{1}{5} \) cup of sugar.

Question 8: Construct a diagram to show \( \frac{4}{8} - \frac{2}{8} \).

Answer: Student draws a rectangle divided into 8 parts, shading 4, then erases 2, leaving 2 shaded parts.

Question 9: Find the value of: \( \frac{9}{12} - \frac{3}{12} \).

Answer: 6/12 or 1/2

Question 10: Explain why \( \frac{2}{3} - \frac{1}{3} \) equals \( \frac{1}{3} \).

Answer: Because when subtracting proper fractions with the same denominator, subtract the numerators: 2 - 1 = 1, over the same denominator 3.