**21. Do you know the answer to this one?**

**2 ^{3} = ?**

- 2
- 4
- 6
- 8

**22. Do you know the answer to this question?**

**What is 2648 to two significant figures?**

- 2600
- 2640
- 2650
- 2700

**23. Can you answer this question?**

**Which of these is 3% equivalent to?**

- 0.003
- 0.03
- 0.3
- 300

**24. What is the answer here?**

**-5 x -6 = ?**

- -90
- -30
- 30
- 90

**25. How many triangles can you count?**

- 10
- 12
- 14
- 16

**26. What does ‘X’ equal here?**

**150 – x = 87**

- 53
- 57
- 63
- 67

**27. What is ‘Y’ equivalent to?**

**90 x Y = 450**

- 5
- 6
- 7
- 8

**28. Tell us which digits have been replaced by question marks in this sum.**

**?1 – 2? = 34**

- 4, 5
- 5, 6
- 6, 7
- 8, 9

**29. Calculate the correct answer to this equation.**

**16.72 x 5 = ?**

- 81.5
- 83.6
- 87.1
- 91.3

**30. Do you know the answer to this conundrum?**

**√324 = ?**

- 16
- 18
- 20
- 22