Class 9 Number Systems Worksheet

A printable practice sheet. Press the button, then choose Print or Save as PDF (A4). The answer key is separate so you can print it on its own.

Curriculum note: 'Number System' is a unit in the CBSE Class 9 Mathematics syllabus for 2026-27 (published by CBSE in April 2026, per secondary sources we checked). We could not confirm exactly which sub-topics, such as irrational numbers and surds, appear in the 2026-27 syllabus, so please check the official CBSE syllabus and your textbook before relying on this quiz for exam preparation.

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Class 9 Number Systems – Practice Worksheet

Name:

Date:

Marks: / 10

Instructions: Answer all 10 questions. Circle the correct option and show your working in the space given.

  1. Which of these numbers is irrational?

    • (A) 0.25
    • (B) 4/5
    • (C) √9
    • (D) √2

    Working:

    Answer:

  2. Which of these is a rational number between 1 and 2?

    • (A) √5
    • (B) 3/2
    • (C) π
    • (D) √3

    Working:

    Answer:

  3. Write 0.333... (3 repeating) as a fraction.

    • (A) 3/10
    • (B) 33/100
    • (C) 1/3
    • (D) 1/30

    Working:

    Answer:

  4. The number √16 is:

    • (A) A rational number
    • (B) An irrational number
    • (C) Not a real number
    • (D) A negative number

    Working:

    Answer:

  5. The decimal expansion of 7/8 is:

    • (A) Non-terminating and repeating
    • (B) Non-terminating and non-repeating
    • (C) Not possible to find
    • (D) Terminating

    Working:

    Answer:

  6. What is (2 + √3)(2 − √3)?

    • (A) 7
    • (B) 4
    • (C) 1
    • (D) 2 − 3√3

    Working:

    Answer:

  7. Rationalise the denominator of 1/√2.

    • (A) 1/2
    • (B) √2/2
    • (C) √2
    • (D) 2√2

    Working:

    Answer:

  8. Simplify: 2³ × 2⁴

    • (A) 2¹²
    • (B) 4⁷
    • (C) 2¹
    • (D) 2⁷

    Working:

    Answer:

  9. What is the value of 27^(1/3)?

    • (A) 3
    • (B) 9
    • (C) 81
    • (D) 1/3

    Working:

    Answer:

  10. Which of these numbers lies between 3 and 4?

    • (A) √5
    • (B) √20
    • (C) √10
    • (D) √16

    Working:

    Answer:

Original questions by LearnWise Practice Hub.

Show answer key and explanations

Class 9 Number Systems – Answer Key

  1. Answer: (D) √2

    √9 = 3, 0.25 = 1/4 and 4/5 are all rational. √2 cannot be written as p/q, so it is irrational.

  2. Answer: (B) 3/2

    3/2 = 1.5 is rational and lies between 1 and 2. √5 ≈ 2.24 is outside, π ≈ 3.14 is outside, and √3 is irrational.

  3. Answer: (C) 1/3

    Let x = 0.333... Then 10x = 3.333... Subtract: 9x = 3, so x = 3/9 = 1/3.

  4. Answer: (A) A rational number

    √16 = 4, which is an integer and so can be written as 4/1. It is rational.

  5. Answer: (D) Terminating

    Dividing 7 by 8 gives 0.875 exactly, so the expansion ends. It is terminating.

  6. Answer: (C) 1

    Use (a + b)(a − b) = a² − b². Here 2² − (√3)² = 4 − 3 = 1.

  7. Answer: (B) √2/2

    Multiply top and bottom by √2: (1 × √2)/(√2 × √2) = √2/2.

  8. Answer: (D) 2⁷

    When multiplying powers with the same base, add the exponents: 2³ × 2⁴ = 2^(3+4) = 2⁷.

  9. Answer: (A) 3

    27^(1/3) is the cube root of 27. Since 3 × 3 × 3 = 27, the answer is 3.

  10. Answer: (C) √10

    3² = 9 and 4² = 16, so a number between 3 and 4 has a square between 9 and 16. √10 fits; √5 < 3, √20 > 4 and √16 = 4.