What are some common conversion factors I should remember?

In one line

The rule

Conversion factors are fixed numbers used to change a quantity from one unit to another, without changing its value.

Let's understand it simply

Imagine you are buying rice at the market. The shopkeeper says the price is ₹40 per kilogram, but you only need 500 grams. To know the price, you must change grams to kilograms. Here, you use a conversion factor: 1000 grams = 1 kilogram. These numbers are like shortcuts that help you compare, measure, or calculate easily.

How it works

1. Find out what units you have and what you need (e.g., grams to kilograms).
2. Write the conversion factor (e.g., 1 kg = 1000 g).
3. Decide if you need to multiply or divide (e.g., grams to kilograms: divide by 1000).
4. Do the calculation.

Where you see it in real life

• Cooking: Changing 2 litres of milk to millilitres (1 litre = 1000 millilitres).
• Cricket: Converting a 22-yard pitch to metres (1 yard ≈ 0.9144 metres).
• Buying vegetables: Changing 250 grams to kilograms (1 kg = 1000 g).
• Travelling: Changing 5 kilometres to metres (1 km = 1000 m).
• Temperature: Changing Celsius to Fahrenheit (°F = (°C × 9/5) + 32).
• Money: Changing rupees to paise (1 rupee = 100 paise).

Why it matters

• Helps in exams when units are different in the question and answer.
• Needed in science labs to measure chemicals correctly.
• Useful in daily life for shopping, cooking, or travelling.
• Makes calculations faster and avoids mistakes.

Common mistakes

• Mixing up when to multiply or divide (e.g., grams to kilograms: divide by 1000, not multiply).
• Forgetting the correct conversion number (e.g., thinking 1 kg = 100 g instead of 1000 g).
• Not checking if both units are in the same system (e.g., mixing metric and imperial units).

Remember it

"Kilo means 1000" — so always think 1 kg = 1000 g, 1 km = 1000 m, 1 litre = 1000 ml.

Some common conversion factors to remember