Rounding and Measurement Precision

Name:

Date:

Measuring tools and numbers illustration

🎯 WALT (We Are Learning To)

• Round numbers to the degree of precision required in context

• Connect rounding to practical measurement situations

• Explain why rounding is important in real-world problems

Success Criteria:

I can round numbers accurately and explain why rounding matters in measurement.

📏 Part 1: Rounding in Context

1. A carpenter measures a piece of timber as 2.847 metres. Round this measurement to the nearest:

a) Tenth of a metre: _________ m

b) Centimetre: _________ m

c) Whole metre: _________ m

2. Sarah weighs ingredients for baking. Her scales show 0.678 kg of flour. Which rounding would be most appropriate for her recipe?

1 kg (nearest whole number)

0.7 kg (nearest tenth)

0.68 kg (nearest hundredth)

3. A running track measures 387.23 metres. For different purposes, we need different precision:

Official race distance: _________ m (nearest metre)

Construction planning: _________ m (nearest 10 metres)

Engineering blueprint: _________ m (nearest centimetre)

4. Circle the measurements that have been rounded appropriately for their context:

Room temperature: 21°C

Medicine dosage: 5 mg

Distance to Auckland: 200 km

Cooking time: 45.6783 minutes

🔍 Part 2: Real-World Problem Solving

5. You're planning a school garden project. The measurements are:

• Garden length: 12.847 m

• Garden width: 8.234 m

• Fence post spacing: 1.67 m

Round each measurement to an appropriate precision for:

a) Ordering materials: Length _____ m, Width _____ m, Post spacing _____ m

b) Marking out the area: Length _____ m, Width _____ m, Post spacing _____ m

6. Explain your rounding choices for question 5:

7. Extension Challenge: A recipe serves 4 people and needs 0.375 kg of mince. You're cooking for 13 people. Calculate how much mince you need, then round to an appropriate precision for shopping. Show your working:

8. Reflection: How does the Māori concept of tika (correctness/accuracy) relate to choosing appropriate rounding in measurement? Write 2-3 sentences: