“Based on Latest CBSE 2026–27 Syllabus | Includes Answer Key”
Preparing for Class 9 Maths becomes easier when you practice high-quality multiple choice questions. The Number System chapter is one of the most important topics in the CBSE 2026–27 syllabus and forms the foundation for higher mathematics.
In this post, you will find 70 carefully selected MCQs on Number System, including basic, conceptual, and HOTS questions. These questions are designed to improve your understanding of real numbers, irrational numbers, laws of exponents, and decimal expansions.
These MCQs follow the latest CBSE exam pattern and help students build strong problem-solving skills. Whether you are preparing for school exams, Olympiads, or competitive tests, practicing these questions regularly will boost your speed and accuracy.
👉 Attempt all questions first, then scroll down to check the final answer key.
🔹 Multiple Choice Questions
1. Which of the following is a rational number?
A) √2
B) √5
C) 0.25
D) π
2. The decimal expansion of 1/3 is:
A) Terminating
B) Non-terminating recurring
C) Non-recurring
D) Irrational
3. √16 is equal to:
A) 4
B) –4
C) ±4
D) 8
4. Which of the following is irrational?
A) 0.333…
B) 22/7
C) √7
D) 5/2
5. The product of a rational and an irrational number is:
A) Always rational
B) Always irrational
C) Sometimes rational
D) None
6. Which of the following is a terminating decimal?
A) 1/6
B) 1/7
C) 3/8
D) 2/3
7. The value of √49 is:
A) 7
B) –7
C) ±7
D) 14
8. π is:
A) Rational
B) Irrational
C) Integer
D) Whole number
9. The square root of a negative number is:
A) Real
B) Rational
C) Not real
D) Integer
10. Which is a perfect square?
A) 50
B) 64
C) 72
D) 90
11. √2 + √3 is:
A) Rational
B) Irrational
C) Integer
D) Whole
12. The decimal expansion of 5/8 is:
A) Terminating
B) Non-terminating
C) Non-recurring
D) Irrational
13. 0.999… is equal to:
A) 1
B) 0.9
C) Less than 1
D) More than 1
14. The value of 2³ × 2² is:
A) 2⁵
B) 4⁵
C) 2⁶
D) 4⁶
15. The value of (3²)³ is:
A) 3⁵
B) 3⁶
C) 9⁶
D) 27³
16. Which of the following is not a real number?
A) √5
B) –3
C) √–1
D) 0
17. √0 is equal to:
A) 0
B) 1
C) Undefined
D) –1
18. If x² = 81, then x =
A) 9
B) –9
C) ±9
D) 81
19. Which number lies between √2 and √3?
A) 1.4
B) 1.5
C) 1.7
D) 1.9
20. The value of √(121/144) is:
A) 11/12
B) 12/11
C) 121/144
D) 1
21. Which of the following is an integer?
A) 3.5
B) –2
C) √2
D) 1/2
22. The decimal expansion of 2/11 is:
A) Terminating
B) Non-terminating recurring
C) Irrational
D) Whole
23. √81 + √16 =
A) 13
B) 17
C) 9
D) 5
24. The value of 10⁰ is:
A) 0
B) 1
C) 10
D) Undefined
25. Which is a whole number?
A) –1
B) 0
C) 1/2
D) √2
26. The rationalizing factor of √5 is:
A) √5
B) 5
C) 1/√5
D) 2√5
27. The value of √(25 × 16) is:
A) 20
B) 400
C) 40
D) 10
28. Which of the following is not a perfect cube?
A) 27
B) 64
C) 125
D) 50
29. The cube root of 64 is:
A) 2
B) 4
C) 8
D) 16
30. √2 × √8 =
A) 4
B) 16
C) 2
D) 8
31. Which number is between 0 and 1?
A) 2
B) –1
C) 0.5
D) 3
32. The value of (–3)² is:
A) –9
B) 9
C) 6
D) –6
33. Which is a natural number?
A) 0
B) 1
C) –1
D) 1/2
34. The value of √(9/16) is:
A) 3/4
B) 4/3
C) 9/16
D) 1
35. Which is not rational?
A) 5
B) 7/2
C) √3
D) 0
36. The value of 2⁴ is:
A) 8
B) 16
C) 32
D) 64
37. The square root of 225 is:
A) 25
B) 15
C) 10
D) 5
38. Which number has a non-terminating non-recurring decimal?
A) 1/4
B) 2/5
C) √2
D) 3/8
39. The value of (5² – 3²) is:
A) 16
B) 25
C) 9
D) 8
40. The value of √144 is:
A) 10
B) 11
C) 12
D) 14
41. Which is not an integer?
A) 0
B) –5
C) 3/2
D) 8
42. The value of 7² is:
A) 14
B) 21
C) 49
D) 28
43. Which is a real number?
A) √–4
B) 1/0
C) √5
D) None
44. The value of √(36/49) is:
A) 6/7
B) 7/6
C) 36/49
D) 1
45. Which number is irrational?
A) 0.75
B) 2/3
C) √11
D) 5
46. The value of 3³ is:
A) 9
B) 27
C) 6
D) 18
47. Which is not a whole number?
A) 0
B) 5
C) –1
D) 10
48. √50 can be simplified as:
A) 5√2
B) 25√2
C) 10√2
D) √25
49. The value of (√3)² is:
A) 3
B) √3
C) 6
D) 9
50. Which of the following is true?
A) √2 is rational
B) π is rational
C) 0 is irrational
D) √5 is irrational
🔥 HOTS (Higher Order Thinking Questions) – Q51 to Q70
51. Which of the following is irrational?
A) √18
B) √16
C) 0.125
D) 7/8
52. If √2 + √3 = x, then x² =
A) 5
B) 2 + √6
C) 5 + 2√6
D) 6
53. Which number lies between √5 and √6?
A) 2.1
B) 2.3
C) 2.5
D) 2.7
54. If x = √7 – √5, then x² =
A) 2
B) 12 – 2√35
C) 12 + 2√35
D) 7
55. Which of the following is rational?
A) √2 + √8
B) √18 – √2
C) √50 – √2
D) √9 + √16
56. The decimal expansion of a rational number is always:
A) Terminating
B) Non-terminating recurring
C) Either terminating or recurring
D) Irrational
57. Which of the following is NOT a real number?
A) √(–9)
B) √9
C) –5
D) 3/4
58. If x² = 5, then x is:
A) Rational
B) Irrational
C) Integer
D) Whole
59. If √a = 5, then a =
A) 10
B) 25
C) 15
D) 5
60. Which of the following is irrational?
A) 0.1010010001…
B) 0.333…
C) 1/4
D) 2/5
61. If x = √3 + 1, find x² – 2x
A) 1
B) 2
C) 3
D) 0
62. Which is greater?
A) √2
B) √3
C) √5
D) √7
63. If x = √5, then x³ =
A) 5√5
B) 25
C) 10√5
D) √125
64. If √x = 3√2, then x =
A) 18
B) 6
C) 9
D) 12
65. Which of the following is a perfect square?
A) 200
B) 225
C) 180
D) 250
66. If a = √2 and b = √3, then ab =
A) √6
B) 6
C) 5
D) √5
67. Which is rational?
A) √7 + √11
B) √9 + √16
C) √2 + √3
D) √5 + √6
68. If x = √2, then (x + 1/x) =
A) √2 + 1/√2
B) 3/√2
C) √2
D) 2
69. Which number has terminating decimal expansion?
A) 1/3
B) 2/7
C) 3/25
D) 5/9
70. If √x + √y = 0, then x and y are:
A) Positive
B) Zero
C) Negative
D) Equal
✅ FINAL ANSWER KEY (1–70)
🔹 Answers 1–25
- C
- B
- A
- C
- B
- C
- A
- B
- C
- B
- B
- A
- A
- A
- B
- C
- A
- C
- B
- A
- B
- B
- A
- B
- B
🔹 Answers 26–50
- A
- A
- D
- B
- A
- C
- B
- B
- A
- C
- B
- B
- C
- A
- C
- C
- C
- C
- A
- C
- B
- C
- A
- A
- D
🔹 Answers 51–70 (HOTS)
- A
- C
- B
- B
- D
- C
- A
- B
- B
- A
- A
- D
- A
- A
- B
- A
- B
- B
- C
- B
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