Length Measurement Mastery

Year 7–8 Maths | Measurement Strand

Name:

Date:

📏 Part 1: Choosing the Right Unit

For each question, select the most appropriate unit to measure the object.

1. The length of a pencil.

millimetres (mm)

centimetres (cm)

metres (m)

feet (ft)

2. The width of a fingernail.

millimetres (mm)

centimetres (cm)

metres (m)

kilometres (km)

3. The height of a classroom door.

millimetres (mm)

centimetres (cm)

metres (m)

kilometres (km)

4. A person's height is often listed as 5 feet 9 inches in some countries. Which metric unit would be the best equivalent to use in New Zealand?

millimetres (mm)

centimetres (cm)

metres (m)

kilometres (km)

5. Which two units would be reasonable to use when measuring the length of a classroom desk? (Select all that apply.)

millimetres (mm)

centimetres (cm)

metres (m)

kilometres (km)

🔢 Part 2: Unit Conversions

Use these conversion facts: 10 mm = 1 cm | 100 cm = 1 m | 1 foot ≈ 30.5 cm

6. Convert the following measurements. Show your working.

(a) 85 mm = __________ cm

(b) 3.5 m = __________ cm

(c) 240 cm = __________ m

(d) A shelf is 2 feet long. Approximately how long is this in centimetres? __________ cm

7. A student says: "150 cm is longer than 1.4 m." Is this correct? Circle your answer and explain below.

Yes, it is correct

No, it is incorrect

📐 Part 3: Measure, Estimate & Justify

Use a ruler to complete the practical tasks below.

8. Choose two objects in the classroom. For each object: write the name, estimate the length, measure it, record it in two units, and explain your unit choice.

Object 1: _______________________________

My estimate: __________ Unit I used: __________

Measured length: __________ cm = __________ mm

Why did you choose this unit?

Object 2: _______________________________

My estimate: __________ Unit I used: __________

Measured length: __________ cm = __________ mm

Why did you choose this unit?

9. A builder measures a piece of timber and records it as 1850 mm. Write this measurement in metres and explain why a builder might prefer to use millimetres rather than metres.

1850 mm = __________ m

10. Estimation Challenge: Without measuring, estimate the length of your classroom in metres. Then explain the strategy you used to make your estimate (e.g., comparing to a known length).

My estimate: __________ m