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Tuesday, May 1, 2012

Length, Mass And Volume Of Liquid

LENGTH

You can measure how long things are, or how tall, or how far apart they are. Those are are all examples of length measurements.

Example: This fork is 20 centimeters long

These are the most common measurements:
  • Millimeters
  • Centimeters
  • Meters
  • Kilometers
 id card
Small units of length are called millimeters.
A millimeter is about the thickness of a plastic id card (or credit card).
Or about the thickness of 10 sheets of paper on top of each other.
This is a very small measurement!


When you have 10 millimeters, it can be called a centimeter.
1 centimeter = 10 millimeters
 fingers
 A fingernail is about one centimeter wide.

Two tape measures, one in mm, the other in cm
You might use millimeter or centimeters to measure how tall you are, or how wide a table is, but you would not use them to measure the length of football field. In order to do that, you can switch to meters.

A meter is equal to 100 centimeters.    [1 meter1 meter = 100 centimeters]


                                             The length of this guitar is about 1 meter




Meters might be used to measure the length of a house, or the size of a playground.
And because a centimeter is 10 millimeters:         [1 meter = 1000 millimeters]
 
roadsA kilometer is equal to 1000 meters.
When you need to get from one place to another, you measure the distance using kilometers.
The distance from one city to another or how far a plane travels would be measured using kilometers.

Final thoughts about measuring length:
1 centimeter = 10 millimeters
1 meter        = 100 centimeters
1 kilometer  = 1000 meters 
  
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MASS
 
set of weights
Mass: how much matter is in an object.
We measure mass by weighing, but Weight and Mass are not really the same thing.

These are the most common measurements:
  • Grams
  • Kilograms
  • Tonnes
Grams are the smallest, Tonnes are the biggest.
Let’s take a few minutes and explore how heavy each of these are.

Grams

paperclip A paperclip weighs about 1 gram.
Hold one small paperclip in your hand. Does that weigh a lot? No! A gram is very light. That is why you often see things measured in hundreds of grams.
Grams are often written as g (for short), so "300 g" means "300 grams".
A loaf of bread weighs about 700 g (for a nice sized loaf)

Kilograms

Once you have 1,000 grams, you have 1 kilogram.
1 kilogram = 1,000 grams
A dictionary has a mass of about one kilogram.
Dictionary
Kilograms are great for measuring things that can be lifted by people (sometimes very strong people are needed of course!).
bathroom-scales Kilograms are often written as kg (that is a "k" for "kilo" and a "g" for "gram), so "10 kg" means "10 kilograms".
When you weigh yourself on a scale, you would use kilograms. An adult weighs about 70 kg. How much do you weigh?
But when it comes to things that are very heavy, we need to use the tonne.

Tonne

Once you have 1,000 kilograms, you will have 1 tonne.
1 tonne = 1,000 kilograms
car Tonnes (also called Metric Tons) are used to measure things that are very heavy.
Things like cars, trucks and large cargo boxes are weighed using the tonne.
This car weighs about 2 tonnes.
Tonnes are often written as t (for short), so "5 t" means "5 tonnes".
Final thoughts about measuring weight:

1 kilogram = 1,000 grams
1 tonne = 1,000 kilograms
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VOLUME OF LIQUID

These are the two most common measurements:
  • Milliliters
  • Liters

MilliliterA milliliter (that is "milli" and "liter" put together) is a very small amount of liquid.
Here is a milliliter of milk in a teaspoon.
It doesn't even fill the teaspoon!

If you collect about 20 drops of water, you will have 1 milliliter:
20 drops of water droplets makes about 1 milliliter
And a teaspoon can hold about five milliliters:
1 teaspoon of liquid Teaspoonful is about 5 milliliters

Milliliters are often written as ml (for short), so "100 ml" means "100 milliliters".
Here we have 150 ml of milk in a measuring cup.
It doesn't say "150" ... it says "50" ... but it is half-way between 100 and 200 so you can figure out it is 150 ml.



liter water

Liter

A liter is just a bunch of milliliters put all together. In fact, 1000 milliliters makes up 1 liter:
1 liter = 1,000 milliliters
This jug has exactly 1 liter of water in it.
Liters are often written as L (for short), so "3 L" means "3 Liters".
Milk, soda and other drinks are often sold in liters.
The next time you are at the store take a minute and look on the labels to see how many liters (or milliliters) are in each container!
Liter is abbreviated L (some people use lowercase l, but that looks too much like 1). Another way of thinking about a liter is:
  • A box that is 0.1 meters (10 cm) on each side,
  • One square meter that is millimeter thick.


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