A surd is an irrational number expressed as the root of a rational number.

Rationalising a single term denominator

Maths

In the prior unit, pupils explored the concept of square root, including calculating this on their calculators. In this unit, pupils work with surds and the notion that a surd is both an operation and the result of that operation.

Surds

True or false? $$\sqrt {7 {1\over9}}$$ is in its simplest form.

Simplify $$\sqrt {30 {1\over4}}$$. Write your answer in decimal notation. 

What should you multiply by to rationalise $$5 \over \sqrt {5}$$ ?

$${3 + 2\sqrt {3}} \over {3 + 2\sqrt {3}}$$

What should you multiply by to rationalise $${3 + 2\sqrt {3}} \over \sqrt {7}$$ ?

Rationalise the denominator $${3\sqrt {3}} \over {2\sqrt {2}}$$

Rationalise the denominator $${36} \over {3\sqrt {4}}$$

Which of these fractions are written in simplest form?

Evaluate $$\sqrt {41} \times \sqrt {41}$$

Evaluate $$\sqrt {0.3999} \times \sqrt {0.3999}$$

If the radicand is rational, then squaring the surd results in a {{}} number.

True or false? An equivalent fraction can be created by multiplying the denominator by the scale factor.

This lesson will be removed by end of Summer Term 2025.

Rationalising a single term denominator

Lesson outcome

This lesson will be removed by end of Summer Term 2025.