2,2,6,9的24点答案：
1:2 × (2 × 9 - 6)
2:2 × ((2 × 9) - 6)
3:2 × (6 ÷ 2 + 9)
4:2 × ((6 ÷ 2) + 9)
5:2 × (9 × 2 - 6)
6:2 × ((9 × 2) - 6)
7:2 × (9 + 6 ÷ 2)
8:2 × (9 + (6 ÷ 2))
9:(2 × 9 - 6) × 2
10:((2 × 9) - 6) × 2
11:(6 ÷ 2 + 9) × 2
12:((6 ÷ 2) + 9) × 2
13:(9 × 2 - 6) × 2
14:((9 × 2) - 6) × 2
15:(9 + 6 ÷ 2) × 2
16:(9 + (6 ÷ 2)) × 2
