Weight, Perimeter & Data Handling

Part 1 — How Heavy? How Light? (Weight)

Measuring Weight

• Gram (g) : For LIGHT things — a paperclip (~1 g), a pencil (~10 g)
• Kilogram (kg) : For HEAVY things — a bag of rice (5 kg), a person (~30 kg)
• 1 kg = 1,000 g

Comparing Weights

• An apple (~150 g) is LIGHTER than a watermelon (~3 kg)
• A car (~1,200 kg) is HEAVIER than a bicycle (~15 kg)

Practice

1. How many grams in 2 kg? (Answer: 2,000 g)
2. A sack of wheat weighs 25 kg. How many grams? (Answer: 25,000 g)
3. Which is heavier: 500 g of cotton or 500 g of iron? (Answer: SAME — both are 500 g!)

Part 2 — Fields and Fences (Perimeter)

What Is Perimeter?

The PERIMETER is the DISTANCE AROUND the outside of a shape.

• The fence around a field = the PERIMETER of that field
• Perimeter of a RECTANGLE = 2 × (Length + Width)
• Perimeter of a SQUARE = 4 × Side

Practice

1. A square field has a side of 10 m. Perimeter = ? (Answer: 40 m)
2. A rectangular field is 20 m long and 10 m wide. Perimeter = ? (Answer: 60 m)
3. If a farmer needs 200 m of fencing, what could be the length and width of his field?

Part 3 — Smart Charts (Data Handling)

What Is Data?

DATA is INFORMATION. We collect data, then show it in CHARTS so it's easy to understand.

Types of Charts

• PICTOGRAPH: Uses PICTURES to show numbers. 😊 = 5 students.
• BAR GRAPH: Uses BARS of different heights.
• TALLY MARKS: |||| = 4. |||| = 5.

Make Your Own Chart

Survey your class: 'What is your FAVOURITE FRUIT?'

Draw a bar graph showing this data!

Practice

A pictograph shows: ☆ = 5 books. Library has ☆☆☆☆. How many books? (Answer: 4 × 5 = 20 books)