Weight — gram and kilogram

For weighing we use two main units:

• Gram (g) — for light things.
• Kilogram (kg) — for heavy things.

Remember: 1 kilogram = 1 000 grams.

When grams

Grams suit small things:

• Apple ≈ 150 g
• Banana ≈ 120 g
• Bag of sweets ≈ 100 g
• Bar of chocolate ≈ 100 g

When kilograms

We use kilograms for bigger things:

• Sack of potatoes ≈ 5 kg
• Cat ≈ 4 kg
• Bicycle ≈ 12 kg
• Second-grader (the child themselves) ≈ 20–25 kg

Trick: how to decide

Hold a bag of sugar in your hand (1 kg). That is a kilogram.

• Lighter? Probably count in grams.
• Heavier? Count in kilograms.

Conversion: kilogram ↔ gram

• 1 kg = 1 000 g
• 2 kg = 2 000 g
• 500 g = half a kilogram
• 1 500 g = 1 kg + 500 g = a kilo and a half

How to weigh

1. Put the thing on the scale.
2. See where the needle stops (or the number on the display).
3. Read both the number and the unit.

Common mistakes:

• With a kitchen scale: reading kg instead of g, or the other way round.
• With a digital scale: not noticing the unit next to the number.

Compare weights

Same idea as with lengths:

Heavier − lighter = difference.

Example: book = 400 g, magazine = 150 g.

400 − 150 = 250 g. The book is 250 g heavier.

Summary

• Gram (g) for light, kilogram (kg) for heavy things.
• 1 kg = 1 000 g.
• When weighing, read both the number and the unit — watch which one is shown!
• Difference: heavier − lighter.