Year 8

# Rounding to significant figures (Part 1)

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## Lesson details

### Key learning points

- In this lesson, we will be introduced to significant figures and understand the concept of degrees of accuracy. We will also learn how to round whole numbers to a given significant figure.

### Licence

This content is made available by Oak National Academy Limited and its partners and licensed under Oak’s terms & conditions (Collection 1), except where otherwise stated.

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### 6 Questions

Q1.

What does this symbol mean? ≈

Closely linked to

Equal to

Not equal to

Q2.

Find an approximation for:

18

27

27.3

Q3.

A student is thinking of an approximate value for √(67 ). What should her answer be?

2√(17) because that is the answer my calculator gives

8.24 because that is the exact answer to 2 d.p.

9 because 67 is closer to 70

Q4.

Find an approximation for:

10.5

15

22.5

Q5.

Find an approximation for:

25

44

55.7

Q6.

Why is the approximation to this calculation greater than the actual answer?

Carlos approximate answer is wrong.

Carlos rounded down when he was approximating

### 6 Questions

Q1.

What does degree of accuracy mean?

How long a measurement is

How many decimal points in a number

Measurements only rounded to a given significant figure

Q2.

How many significant figures does 0.0045 have?

1 s.f.

4 s.f.

5 s.f.

Q3.

How many significant figures does 5610 have?

2 s.f.

4 s.f.

Q4.

Rounding 405.3 to the nearest integer is the same as rounding to ________ significant figures.

1 s.f

2 s.f

4 s.f

Q5.

Round 7906 to 3 s.f.

7900

7916

8000

Q6.

What does significant figure tell us?

How many non-zero digit in a number

Significant figure tell us how many numbers after the decimal point