**Errors in Measurement**

Starter

Think of a number that rounds to 2400 when rounded to 2 significant figures.

Can you think of a smaller one?

A bigger one?

Can you think of the smallest one?

The biggest one?

Writing errors

A length, l, is measured as 5.7 metres to 1 d.p.

(a) The largest possible error =

(b) the range of values that l could be is:

**L.O. - To understand the errors in measurement and represent these errors using inequalities.**

Writing errors

A length, l, is measured as 5.7 metres to 1 d.p.

(a) The largest possible error =

0.05 metres

(b) the range of values that l could be is:

5.65 < l < 5.75

Writing errors

A mass, m, is measured as 350 kilograms to the nearest 10kg.

(a) The largest possible error =

5 kg

(b) the range of values that l could be is:

345 < m < 355

Writing errors

A mass, m, is measured as 350 kilograms to the nearest 10kg.

(a) The largest possible error =

(b) the range of values that l could be is:

Main Activity 1

Complete the following table

A note on truncation

A person is 15 years old.

What is the maximum possible error in this statement?

The range of values the age can be is:

Main Activity 1

Complete the following table

Starter

Think of a number that rounds to 2400 when rounded to 2 significant figures.

Can you think of a smaller one?

A bigger one?

Can you think of the smallest one?

2350

The biggest one?

No, you cant

**Key**

examples

examples

**Activities**

**Activity**

Answers

Answers

Worked

Example

Worked

Example

Worked

Example

5.7

5.65

5.75

350

345

355

A note on truncation

A person is 15 years old.

What is the maximum possible error in this statement?

364 days

The range of values the age can be is:

15 < A < 16

Plenary

Use inequalities to express the maximum error in truncating this number in the calculator:

Plenary

Use inequalities to express the maximum error in truncating this number in the calculator:

960000 < x < 969999