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## Class 6 (Old)

### Course: Class 6 (Old)>Unit 1

Lesson 3: Large numbers in practice

# 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!
• “1 Parsec = 30,856,776,000...”
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
• do not upvote me please
• Yes, many things
For example - An atom is made up of protons, neutrons & electrons which are made up of 3 quarks, but those are just the things that make particles up. There are like 1080 different types of particles! (That's just an understatement) This is where String Theory comes in. String Theory states that all particles are strings that vibrate at a certain frequency and each frequency corresponds to a particle, and how many possible frequencies are possible? ♾️! So we can just say that a particle is a string vibrating at a certain frequency ( probably in the 11th dimension, so if String Theory is true, we live in an 11 dimensional universe) That was a looooooooong comment, wasn't it? Also, check your grammar, it's not "is there anything smaller than a adam" It's "Is there anything smaller than an atom?"
• I'm not aware of anything called a mini-meter, but there are smaller parts of a meter. As follows:

Millimeter - 1000th of a meter
Centimeter - 100th of a meter
Decimeter - 10th of a meter

Note the beginning of each of those words. Other words that start with those beginnings give you a clue as to what measurement is being talked about. For example:
mill = 1000 - think millenium or 1000 years
cent = 100 - think century or 100 years - 100 cents per dollar
dec = 10 - think decade or 10 years
• Right, there's nothing called as mini-meter and still there are smaller units than that.

micrometer - 1 millionth of a meter (0.000000001 m)
nanometer - 1 billionth of a meter (0.000000000001 m)
picometer - 1 trilionth of a meter (0.000000000000001 m)
femtometer - 1 quadrillionth of a meter (0.000000000000000001 m)
attometer - 1 quintillionth of a meter (0.000000000000000000001 m)
zeptometer - 1 sextillionth of a meter (0.000000000000000000000001 m)
yoctometer - 1 septillionth of a meter (0.000000000000000000000000001 m)
rontometer - 1 octillionth of a meter
(0.000000000000000000000000000001 m)
quectometer - 1 nonillionth of a meter
(0.000000000000000000000000000000001 m)