Metric System

The metric system is a common international measurement system introduced to provide uniform values for trade and everyday life. It replaced older methods that relied on human body parts, ensuring people around the world measure mass, volume, and length using the exact same standards.

Why the system was introduced

Until the sixteenth century, people measured goods using arm lengths or handfuls to keep track of trade. Because hand sizes and arm lengths vary from person to person, these differences created many disputes in business. A single, shared system was needed so that measurements remained fair and equal everywhere in the world.

The three basic units

• Gram is the standard unit used to measure the mass of an object.
• Liter is the standard unit used to measure the volume of an object.
• Meter is the standard unit used to measure the length or distance of an object.

Prefixes and unit conversion

The sentence Kamal Hassan doesn't usually drink chocolate milk gives the first letter of each prefix in order: kilo, hecto, deca, the base unit, deci, centi, and milli. Units with kilo, such as kilograms and kilometers, measure large masses and long distances, while centi and milli measure small amounts. In the conversion chart, converting from a large unit to a smaller unit requires multiplying by ten for each step, so one kilogram multiplied by ten three times equals one thousand grams. Converting from a small unit to a larger unit requires dividing by ten for each step, so one hundred centimeters divided by ten twice equals one meter.

Additional units for mass and length

• One quintal is equal to one hundred kilograms.
• One ton is equal to one thousand kilograms, which is used to measure very heavy objects such as ships and large whales.
• One inch is equal to two point five four centimeters.
• One foot is equal to thirty point four eight centimeters, which explains why a thirty-centimeter ruler is commonly referred to as a one-foot scale.