What is a Stone (Weight)?

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Grade Level:

Pre-School – Class 2

All domains without exception

Definition

What is it?

A 'stone' is an old unit used to measure weight, mainly in the UK and Ireland. One stone is equal to 14 pounds (lbs) or approximately 6.35 kilograms (kg). It's still commonly used to measure body weight.

Simple Example

Quick Example

Imagine you want to know your weight. If a weighing scale shows your weight as 5 stone, it means you weigh 5 x 14 = 70 pounds. In kilograms, that would be roughly 5 x 6.35 = 31.75 kg, which is similar to the weight of about 3 large school bags.

Worked Example

Step-by-Step

QUESTION: Your friend tells you their dog weighs 2.5 stone. How much does the dog weigh in kilograms?

Step 1: Understand the conversion. We know 1 stone = 14 pounds.
---Step 2: Convert stone to pounds. Dog's weight in pounds = 2.5 stone * 14 pounds/stone = 35 pounds.
---Step 3: Understand the conversion from pounds to kilograms. We know 1 pound is approximately 0.4536 kilograms.
---Step 4: Convert pounds to kilograms. Dog's weight in kilograms = 35 pounds * 0.4536 kg/pound.
---Step 5: Calculate the final weight. Dog's weight = 15.876 kg.
---ANSWER: The dog weighs approximately 15.88 kg.

Why It Matters

Understanding different units of measurement like 'stone' helps you interpret information from various sources, especially when dealing with international data or historical texts. It's crucial for careers in sports science, nutrition, and international trade, where precise weight conversions are often needed.

Common Mistakes

MISTAKE: Assuming 'stone' is a universal unit used everywhere. | CORRECTION: Remember 'stone' is primarily used in the UK and Ireland for body weight, not globally like kilograms or pounds.

MISTAKE: Confusing 'stone' with a 'rock' or a 'pebble'. | CORRECTION: While the word 'stone' also means a piece of rock, in the context of weight, it's a specific unit of measurement, just like a 'foot' can be a body part or a unit of length.

MISTAKE: Incorrectly converting stone to kilograms by using a simple '1 stone = 10 kg' rule. | CORRECTION: Always remember the correct conversion: 1 stone = 14 pounds, and then 1 pound = approximately 0.4536 kg. So, 1 stone is about 6.35 kg.

Practice Questions

Try It Yourself

QUESTION: If a person weighs 8 stone, what is their weight in pounds? | ANSWER: 112 pounds

QUESTION: A bag of rice weighs 3 stone. How many kilograms does it weigh? (Use 1 stone = 6.35 kg) | ANSWER: 19.05 kg

QUESTION: Your friend in London says they lost 1.5 stone. If they initially weighed 12 stone, what is their new weight in kilograms? (Use 1 stone = 6.35 kg) | ANSWER: Initial weight = 12 * 6.35 = 76.2 kg. Weight lost = 1.5 * 6.35 = 9.525 kg. New weight = 76.2 - 9.525 = 66.675 kg.

MCQ

Quick Quiz

How many pounds are there in 1 stone?

10 pounds

12 pounds

14 pounds

16 pounds

The Correct Answer Is:

One stone is defined as exactly 14 pounds. This is a standard conversion used for this unit of weight.

Real World Connection

In the Real World

When you watch international cricket matches, sometimes commentators might mention a player's weight in 'stone', especially if they are from the UK. Also, if you ever read old recipes or historical documents, you might find weights mentioned in stone, requiring you to convert them to understand the actual quantity.

Key Vocabulary

Key Terms

UNIT: A standard quantity used for measurement | WEIGHT: The measure of how heavy something is | POUND (lb): A unit of weight commonly used in the US and UK | KILOGRAM (kg): The standard international unit of mass/weight | CONVERSION: Changing a quantity from one unit to another

What's Next

What to Learn Next

Now that you understand 'stone' as a unit of weight, you can explore other units like ounces, grams, and tonnes. Learning about these different units will help you convert between them and solve more complex measurement problems in daily life.