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## Basic geometry and measurement

### Course: Basic geometry and measurement>Unit 5

Lesson 1: Estimating length

# Metric system: units of distance

Sal discusses metric units of length or distance such as millimeter, centimeter, meter, and kilometer. Created by Sal Khan.

## Want to join the conversation?

• Is there any thing smaller then a millimeter?
• IDK maybey
• exactly how many centimeters are in 1 inch?(you might have to answer with a decimal point)
• There are exactly 2.5 centimeters in one inch.
• If "centi" is to one-hundredth (1/100) and "milli" is to one-thousandth (1/1000), then why is "'milli'on"=1,000,000.
• The metric system has a different way of categorizing measurements and numbers. The romans, a long time ago, created roman numerals.
• Is there anything bigger than a kilometre ?
• 1 Parsec = 30,856,776,000,000 Kilometers
1 Light Year = 9,460,730,500,000 Kilometers
1 Astronomical Unit = 149,597,871 Kilometers
1 Light Minute = 17,987,547 Kilometers
1 Light Second = 299,792.46 Kilometers
1 Mile = 1.609344 Kilometers
1 Nautical Mile = 1.15078 Mile = 1.852001 Kilometer
• Is there any acronym to remember all of the basic units in the metric system?
• Yes! My favorite one is this:

`King Henry Died By Drinking Chocolate Milk`

KING: Kilo(unit)
HENRY: Hecto(unit)
DIED: Deca(unit)
BY: Base (gram/meter/liter)
DRINKING: Deci(unit)
CHOCOLATE: Centi(unit)
MILK: Milli(unit)

Does it kind of develop a permanent fear of chocolate milk in you? Yes. But is it also incredibly helpful? Absolutely!

Hope this helps!
• mille is Latin for 100. so why do we say hectometer when we mean 100 meters? why do we say millimeter when we wean a 1000th of a meter?
• mille is not latin for 11. Centa is latin for 100. Centimeter means 1/100 of a centimeter.
• does anyone else wish they had that cute little frog?
• is there anything bigger than a kilometer
• Good question!

Yes, there are distance units bigger than a kilometer. Some of these units are much bigger!

A mile is 1.609344 kilometers.
A megameter is 1,000 kilometers.
A gigameter is 1,000,000 kilometers.
A terameter is 1,000,000,000 kilometers.
A light year is about 9,500,000,000,000 kilometers.
A parsec is about 31,000,000,000,000 kilometers.

Have a blessed, wonderful day!