Junior Secondary · Mathematics

Rational & Irrational Numbers: Practice Questions

5 multiple-choice questions marked as you go, and 5 written questions with worked solutions. All on Rational & Irrational Numbers.

10 questions23 marksFree, no account
Question 1
1 mark

Which of the following points on a number line best represents the value of \( -\sqrt{10} \)?

Question 2
1 mark

If \( c = \sqrt{10} \) and \( d = \sqrt{40} \), which of the following operations results in a rational number?

Question 3
1 mark

A rectangle \(ABCD\) has a length of \( \sqrt{125} + \sqrt{5} \) cm and a width of \( \sqrt{80} - \sqrt{20} \) cm. Find the perimeter of the rectangle.

Question 4
1 mark

Which of the following integers is the closest to the value of \( \sqrt{130} \) on a number line?

Question 5
1 mark

Given that \( a = \sqrt{5} \) and \( b = \sqrt{20} \), which of the following expressions results in a rational number?

Question 6
2 marks

Determine whether the value of \( \sqrt{0.81} \) is a rational or an irrational number.

Write your answer out first, then check it against the worked solution.

Question 7
3 marks

Determine whether the value of the expression \( \sqrt{1.44} - \sqrt[3]{-27} \) is a rational or an irrational number. Show your calculation steps.

Write your answer out first, then check it against the worked solution.

Question 8
5 marks

If \( x = \sqrt{2} \), evaluate the value of the algebraic fraction \( \frac{x^4 - 4}{x^2 + 2} \) and state whether the result is rational or irrational.

Write your answer out first, then check it against the worked solution.

Question 9
3 marks

(a) Evaluate the value of \( \sqrt[3]{-125} \).
(b) State whether the value obtained in (a) is a rational number or an irrational number. Justify your answer.
(c) If this value is represented on a number line, identify if it lies between two integers or if it is exactly an integer. If it lies between integers, name them.

Write your answer out first, then check it against the worked solution.

Question 10
5 marks

In a right-angled triangle, the lengths of the two legs are \( \sqrt{12} \) cm and \( \sqrt{8} \) cm.
(a) Express the lengths of the two legs in the simplest surd form \( a\sqrt{b} \).
(b) Calculate the area of the triangle. Is the result a rational or an irrational number?
(c) Using Pythagoras' Theorem, find the length of the hypotenuse. Express your answer in its simplest surd form.

Write your answer out first, then check it against the worked solution.

* The content provided by thinka is generated by AI and may not always be accurate or up-to-date. Please use it as a supplementary resource and verify with official materials.

You've seen the model answer. Now get yours marked.

This page can show you how a good answer looks. It cannot tell you what your answer was missing. thinka marks your written work against the real mark scheme in about 15 seconds.

Want more questions like these? Get a fresh set on this topic, marked as you go.

Practise More