Sure! Here are 20 multiple-choice questions with answers for Grade 6 Mathematics:

1. What is the value of 5 + 3 x 2? a) 10 b) 11 c) 13 d) 16 Answer: c) 13

2. Which of the following is a prime number? a) 12 b) 15 c) 17 d) 20 Answer: c) 17

3. What is the value of 3/4 + 1/2? a) 1/8 b) 5/8 c) 7/8 d) 9/8 Answer: b) 5/8

4. What is the area of a rectangle with length 8 cm and width 5 cm? a) 13 cm² b) 35 cm² c) 40 cm² d) 45 cm² Answer: b) 35 cm²

5. What is the value of 7² - 3²? a) 16 b) 28 c) 36 d) 40 Answer: c) 36

6. Which of the following fractions is equivalent to 3/5? a) 2/3 b) 4/7 c) 6/10 d) 8/12 Answer: c) 6/10

7. What is the value of 2/3 ÷ 4/5? a) 1/3 b) 5/6 c) 8/15 d) 10/12 Answer: b) 5/6

8. What is the perimeter of a square with side length 6 cm? a) 12 cm b) 18 cm c) 24 cm d) 36 cm Answer: c) 24 cm

9. What is the value of 4 x (2 + 3) - 6? a) 8 b) 14 c) 16 d) 20 Answer: b) 14

10. What is the value of 0.5 + 0.25? a) 0.35 b) 0.5 c) 0.75 d) 1.25 Answer: c) 0.75

11. What is the value of 3/4 x 2/3? a) 1/2 b) 1/3 c) 2/3 d) 3/4 Answer: a) 1/2

12. What is the value of 7 x 0? a) 0 b) 1 c) 7 d) Undefined Answer: a) 0

13. What is the value of 9 - (4 + 2)? a) 1 b) 3 c) 5 d) 7 Answer: c) 5

14. What is the value of 5² + 3²? a) 16 b) 25 c) 34 d) 64 Answer: b) 25

15. What is the value of 1/2 + 1/3 + 1/4? a) 1/9 b) 5/12 c) 11/12 d) 13/24 Answer: b) 5/12

16. What is the value of 3/4 - 1/2? a) 1/8 b) 1/4 c) 1/2 d) 5/8 Answer: d) 5/8

17. What is the area of a triangle with base 6 cm and height 8 cm? a) 12 cm² b) 24 cm² c) 32 cm² d) 48 cm² Answer: b) 24 cm²

18. What is the value of 2 x (3 + 4) - 5? a) 6 b) 9 c) 11 d) 14 Answer: c) 11

19. What is the value of 0.75 ÷ 0.25? a) 0.3 b) 1.5 c) 2.5 d) 3.0 Answer: c) 2.5

20. What is the perimeter of a rectangle with length 10 cm and width 4 cm? a) 14 cm b) 18 cm c) 24 cm d) 28 cm Answer: d) 28 cm

I hope these questions help you prepare for your national examination! Good luck!