Measuring Weight in kg and g
Weight tells us how heavy an object is. In Class 3, you learn to measure weight using two units: kilogram (kg) for heavy objects and gram (g) for light objects.
A bag of rice is measured in kg. A small packet of spice is measured in g. Knowing both units and how to convert between them is an important skill.
What is Measuring Weight in kg and g - Class 3 Maths (Measurement)?
Kilogram (kg) is used for measuring heavier objects.
Gram (g) is used for measuring lighter objects.
1 kilogram = 1000 grams | 1 kg = 1000 g
Measuring Weight in kg and g Formula
kg to g → × 1000 | g to kg → ÷ 1000
Types and Properties
Examples of weights:
| Object | Approximate Weight | Unit |
|---|---|---|
| A pencil | 5 g | grams |
| An apple | 150 g | grams |
| A packet of butter | 500 g | grams |
| A bag of flour (atta) | 5 kg | kilograms |
| A watermelon | 3 kg | kilograms |
| A school bag (full) | 4 kg | kilograms |
Solved Examples
Example 1: Convert kg to g
Question: Convert 3 kg to grams.
Think:
- 1 kg = 1000 g
- 3 kg = 3 × 1000 = 3000 g
Answer: 3 kg = 3000 g.
Example 2: Convert g to kg
Question: Convert 4000 g to kg.
Think:
- 4000 ÷ 1000 = 4
Answer: 4000 g = 4 kg.
Example 3: Mixed Units to Grams
Question: Express 2 kg 500 g in grams.
Think:
- 2 kg = 2000 g
- 2000 + 500 = 2500 g
Answer: 2 kg 500 g = 2500 g.
Example 4: Grams to Mixed Units
Question: Express 3750 g in kg and g.
Think:
- 3750 ÷ 1000 = 3 remainder 750
Answer: 3750 g = 3 kg 750 g.
Example 5: Word Problem — Fruits
Question: Ria buys 2 kg of apples and 500 g of grapes. What is the total weight?
Think:
- 2 kg = 2000 g
- 2000 + 500 = 2500 g = 2 kg 500 g
Answer: Total weight = 2 kg 500 g.
Example 6: Addition of Weights
Question: A bag of sugar weighs 1 kg 750 g. A bag of salt weighs 1 kg 300 g. Total weight?
Think:
- kg: 1 + 1 = 2 kg
- g: 750 + 300 = 1050 g = 1 kg 50 g
- Total: 2 + 1 = 3 kg 50 g
Answer: Total = 3 kg 50 g.
Example 7: Subtraction of Weights
Question: A watermelon weighs 4 kg. After cutting, the rind (skin) weighs 750 g. What is the weight of the edible part?
Think:
- 4 kg = 4000 g
- 4000 − 750 = 3250 g = 3 kg 250 g
Answer: Edible part = 3 kg 250 g.
Example 8: Comparing Weights
Question: Which is heavier: 2 kg or 1800 g?
Think:
- 2 kg = 2000 g
- 2000 > 1800
Answer: 2 kg is heavier.
Example 9: Choosing the Right Unit
Question: Would you measure a mango in kg or g?
Think:
- A mango weighs about 200-300 g.
- Grams is the better unit.
Answer: Measure in grams (g).
Key Points to Remember
- 1 kg = 1000 g.
- Use kg for heavy things (rice bags, fruits in bulk, body weight).
- Use g for light things (pencils, spices, small food items).
- To convert kg to g, multiply by 1000.
- To convert g to kg, divide by 1000.
- For addition/subtraction, convert to the same unit first.
- A weighing balance or digital scale measures weight.
Practice Problems
- Convert 5 kg to grams.
- Convert 6000 g to kg.
- Express 1 kg 250 g in grams only.
- Express 4500 g in kg and g.
- Aman buys 3 kg of potatoes and 1 kg 500 g of onions. What is the total weight?
- Which is heavier: 3500 g or 3 kg?
- A packet of biscuits weighs 200 g. How many packets make 1 kg?
Frequently Asked Questions
Q1. What is the difference between kg and g?
Kilogram (kg) is used for heavier things. Gram (g) is for lighter things. 1 kg = 1000 g.
Q2. How do I convert kg to g?
Multiply by 1000. For example, 2 kg = 2000 g.
Q3. How do I convert g to kg?
Divide by 1000. For example, 3000 g = 3 kg.
Q4. What weighs about 1 kg?
A packet of butter (1 kg), a small bag of sugar, or about 4-5 apples together weigh roughly 1 kg.
Q5. What weighs about 1 g?
A paper clip or a small feather weighs about 1 g.
Q6. How do I add weights in kg and g?
Add kg and g separately. If the grams total is 1000 or more, convert: 1200 g = 1 kg 200 g, and add the extra kg.
Q7. What tool measures weight?
A weighing balance, spring balance, or digital scale measures weight.
Q8. Is this covered in NCERT Class 3?
Yes. NCERT Class 3 Maths covers measuring weight in kg and g, including conversion and word problems about everyday objects.
