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Lesson 1 of 12
  • Year 10
  • Higher

Accuracy of final answers

I can appreciate the accuracy in leaving an answer without carrying out the final operation.

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View unit
Lesson 1 of 12
New
New
  • Year 10
  • Higher

Accuracy of final answers

I can appreciate the accuracy in leaving an answer without carrying out the final operation.

Download all resources
Share activities with pupils

These resources will be removed by end of Summer Term 2025.

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These resources were created for remote use during the pandemic and are not designed for classroom teaching.

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Lesson details

Key learning points

  1. There is always a choice regarding how you represent a value.
  2. You need to consider the most suitable way for the situation.
  3. Rounding reduces accuracy so a rounded answer is not always useful.
  4. There are agreed forms: one operation remaining and the result of the operation would produce a non-terminating decimal.
  5. Surd form is one such acceptable way.

Keywords

  • Recurring decimal - A recurring decimal is one that has a digit or sequence of digits that repeat endlessly.

  • Terminating decimal - A terminating decimal is one that has a finite number of digits after the decimal point.

  • Rational number - A rational number is one that can be written in the form a/b where a and b are integers and b is not equal to 0.

  • Irrational number - An irrational number is one that cannot be written in the form a/b where a and b are integers and b is not equal to 0.

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

Common misconception

Surds are any number with a root symbol.

√4 is not a surd as it is equivalent to 2.


To help you plan your year 10 maths lesson on: Accuracy of final answers, download all teaching resources for free and adapt to suit your pupils' needs...

Pupils may struggle with 0 not being a natural number. Natural numbers are positive whole numbers. 0 is neither positive nor negative and therefore cannot be a natural number.
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This content is © Oak National Academy Limited (2025), licensed on Open Government Licence version 3.0 except where otherwise stated. See Oak's terms & conditions (Collection 2).

Lesson video

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Prior knowledge starter quiz

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6 Questions

Q1.
Which of these numbers is not a whole number?

12
16
7
Correct answer: 2.3

Q2.
Press the $$\pi$$ button on your calculator. What is the sixth digit?

Correct answer: 9
6
5
2

Q3.
Enter $$\sqrt{5}$$ on your calculator. What is the second digit?

Correct Answer: 2, two

Q4.
A circle has a diameter of 3 cm. What is the circumference of the circle to 1 decimal place?

Correct Answer: 9.4, 9.4 cm

Q5.
Enter $$\sqrt[3]{64}$$ on your calculator. What is the answer?

Correct Answer: 4, four

Q6.
Which of these is an example of a recurring decimal?

1.2
1.252525253
Correct answer: $$1.\dot{6}$$
2.222

Assessment exit quiz

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6 Questions

Q1.
True or false? The group of integers includes negative numbers.

Correct answer: True
False

Q2.
A number is one that can be written in the form $$a \over b$$ where $$a$$ and $$b$$ are both integers and $$b \ne 0$$.

Correct Answer: rational

Q3.
Identify the rational number.

$$\pi$$
Correct answer: 0.263
$$\sqrt 3$$
$$\sqrt 2$$

Q4.
Which of these is a surd?

Correct answer: $$\sqrt {21}$$
$$\sqrt {25}$$
$$\sqrt {36}$$
$$\sqrt {49}$$

Q5.
Which of these is a surd?

$$\sqrt[3] {64}$$
$$\sqrt[3] {27}$$
Correct answer: $$\sqrt[3] {16}$$
$$\sqrt[3] 8$$

Q6.
Which of these is a surd?

$$\sqrt {1 \over 25}$$
$$\sqrt {0.25}$$
Correct answer: $$\sqrt {1 \over 6}$$
$$\sqrt {1 \over 49}$$