📏 About Estimation and Measurement

Estimation is making a sensible guess about how long something might be before you measure it. Measurement is using a ruler to find the exact length.

When measuring with a ruler, remember to:

• Start measuring from the 0 mark
• Look carefully at the centimetre and millimetre marks
• Record your answer as a decimal (e.g., 7.3 cm instead of 7 cm 3 mm)
• Keep your eye level with the ruler for accuracy

📋 Measuring Activity

Instructions: Find the following objects around your classroom or home. First, estimate how long you think each object is in centimetres. Write your estimate in the table. Then use a ruler to measure the actual length and record it as a decimal in both centimetres (cm) and millimetres (mm).

🤔 Reflection Questions

a) 5.2 cm = _______ mm

b) 12.7 cm = _______ mm

c) 8.5 cm = _______ mm

For example, if your measurement is 7.5 cm, then:

7.5 cm = 7.5 x 10 = _______ mm