🌟 Measurement – Centimetres 🌟

Hello my dear student! I am Miss Brenda, your kind and caring Grade 4 math teacher 💕

Today we are learning about **Centimetres (cm)**! This is one of the most common units we use every day in Canada for measuring length.

📏 What is a Centimetre?

A **centimetre (cm)** is a unit of length in the metric system. It is bigger than a millimetre but smaller than a metre.

Important Relationships:

1 centimetre (cm) = 10 millimetres (mm)
100 centimetres (cm) = 1 metre (m)

🌟 Real-Life Examples of Centimetres

• Width of a finger is about 1 cm
• Length of a paperclip is about 3–4 cm
• Width of a small notebook is about 15 cm
• Height of a juice box is about 10 cm
• Length of a pencil is about 18 cm

🛠️ Measuring with a Ruler in Centimetres

On a ruler:

Tip: Always start measuring from the 0 mark and make sure the object is straight along the ruler.

✏️ Let’s Practice Together, My Dear Student!

Practice 1: Choose the Best Unit

1. Length of your desk → centimetres or metres
2. Thickness of a coin → millimetres
3. Height of a door → metres
Practice 2: Conversions

1. 50 mm = 5 cm
2. 120 mm = 12 cm
3. 8 cm = 80 mm
4. 1 metre = 100 cm
Practice 3: Word Problems (Canadian Style)

1. Your pencil is 19 cm long. Your eraser is 4 cm long. How much longer is the pencil?
19 cm - 4 cm = 15 cm longer

2. A notebook is 22 cm wide and 28 cm long. What is the perimeter of the notebook? (Perimeter = 2 × length + 2 × width)
2×28 + 2×22 = 56 + 44 = 100 cm
Challenge Question

A ruler is 30 cm long. How many millimetres is that?
300 mm

Fantastic Job, My Dear Student! 🎉

You now understand centimetres very well! You know how they connect to millimetres and metres.

I am so proud of you for learning the Measurement unit step by step. Next time you use a ruler, try measuring things in centimetres.

💕 You are smart. You are kind. You can do hard things.

When you are ready, tell me the next topic (Metres, Kilometres, Mass, Capacity, or anything else) and I will create another beautiful lesson just for you!