Consider the numbers $\sqrt 3$, $6$, $2\frac{1}{2}$, $\pi$, $- 5$, and the sets $\mathbb{N}$, $\mathbb{Z}$, and $\mathbb{Q}$. Complete the following table by placing a tick in the appropriate box if the number is an element of the set.

Note: Accept any symbol for ticks. Do not penalize if candidate had also indicated, by a different symbol, that the number is not an element of the set.

Row $\mathbb{N}$ correct, no extra entries.     (A1)     (C1)

Row $\mathbb{Z}$     (A1)(A1)    (C2)

Note: Award (A1) for each correct tick and no extra entries. Award (A1) only for both ticks correct and 1 extra entry, (A0) otherwise.

Row $\mathbb{Q}$     (A1)(A1)(A1)     (C3)

Note: Award (A1) for each correct tick and no extra entries. Award (A2) only for all 3 correct and one extra entry. Award (A1) only for 2 correct and one extra entry. (A0) otherwise.

[6 marks]

This question was poorly answered with many thinking $\mathbb{Q}$ was the set of irrational numbers. Very few candidates were awarded full marks for this question.