Friday, June 25, 2010


Measuring Metrically with Maggie


Wow, I just flew in from planet Micron. It was a long flight, but well worth it to get to spend time with you!

My name is Maggie in your language (but you couldn't pronounce my real name!)

When I first arrived I couldn't understand how you measure things, but my friend Tom taught me all about measurement, and I am going to share with you everything he taught me.

The first thing Tom told me was that you can measure things using two different systems: Metric and US Standard.

Today is my day to learn Metric !

Tom says that if I understand 10, 100, and 1000 then I will have a very easy time learning the metric system. I wish I had ten fingers!


orange juice

Since it was such a long flight, the first thing I could use is something cold to drink.

But I want to know how much to ask for! So I can get a drink that is not too big or too small.

Tom says I only need to know about:

  • Milliliters
  • Liters


A 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!

Tom says if you collect about 20 drops of water, you will have 1 milliliter:
20 drops of water droplet makes about 1 milliliter
And that a teaspoon can hold about five milliliters:
1 full teaspoon of liquid Teaspoonful is about 5 milliliters

Milliliters are often written as ml (for short), so "100 ml" means "100 milliliters".

But a milliliter is definitely not enough for someone who is thirsty! So Tom told me about liters.

liter  water

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.

Tom says to look on the labels, so the next time you are at the store take a minute and check out how many liters (or milliliters) are in each container!

Now I know that a milliliter is very small, and a liter is like a jug in size, I think I will ask for half a liter of juice!

So this is all you need to know:

1 Liter = 1,000 Milliliters

Mass (Weight)

Next I wanted to eat some chocolate ... so I should learn about mass. You often call it "weight", but it is only because of the gravity on your planet that items have weight!

Tom tells me that to understand mass, I should know these three terms:

  • 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.



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".

Tom tells me a loaf of bread weighs about 700 g


Once you have 1,000 grams, you have 1 kilogram.

1 kilogram = 1,000 grams

A dictionary has a mass of about one kilogram.


Kilograms are great for measuring things that can be lifted by people (sometimes very strong people are needed of course!).


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. Tom weighs about 40 kg. How much do you weigh?

But when it comes to things that are very heavy, we need to use the tonne.


Once you have 1000 kilograms, you will have 1 tonne.

1 tonne = 1,000 kilograms


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 has a mass of about 2 tonnes.

Tonnes are often written as t (for short), so "5 t" means "5 tonnes".

Final thoughts about masst:

1 kilogram = 1,000 grams

1 tonne = 1,000 kilograms


carpenter's rule Measuring how long things are, how tall they are, or how far apart they might be are all examples of length measurements.

Tom says I should know about:

  • Millimeters
  • Centimeters
  • Meters
  • Kilometers
id card

The smallest 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 something that is 10 millimeters, it can be said that it is 1 centimeter.

1 centimeter = 10 millimeters

A fingernail is about one centimeter wide.

You might use centimeters to measure how tall you are, or how wide a table is, but you would not use it to measure the length of football field. In order to do that, you would switch to meters.


1  meter

A meter is equal to 100 centimeters.

1 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.



When you need to get from one place to another, you will need to measure that distance using kilometers. A kilometer is equal to 1,000 meters.

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



I was feeling a bit hot, so I asked Tom how to measure temperature.

So he showed me a thermometer. But I saw 2 sets of numbers!

Tom explained that a thermometer measures in degrees (°) of either Celsius or Fahrenheit.

"Why two scales?", I asked.

Tom said that some people like one scale and some like the other, and that I should learn both!

He then gave me an example: when water freezes the thermometer shows:

  • 0 degrees Celsius on the left side,
  • but on the right side it shows 32 degrees Fahrenheit.

So there can be two numbers for the same thing!

He gave me more examples.

  • A hot sunny day might have a temperature of 30 degrees Celsius but would be 86 degrees in Fahrenheit.
  • Water boils at 100 degrees Celsius or 212 degrees Fahrenheit.
  • And you can bake cookies in your oven at a temperature of 180 degrees Celsius, but that would be 356 degrees Fahrenheit.

I decided to get my own thermometer, so I would learn about all this.


I hope you enjoyed learning all about metric measurement.

Now I must return home. Keep measuring until I see you again!!!!!!!!!



A Decimal Number (based on the number 10) contains a Decimal Point.

Place Value

To understand decimal numbers you must first know about Place Value.

When we write numbers, the position (or "place") of each number is important.

In the number 327:

  • the "7" is in the Units position, meaning just 7 (or 7 "1"s),
  • the "2" is in the Tens position meaning 2 tens (or twenty),
  • and the "3" is in the Hundreds position, meaning 3 hundreds.
Place Value
"Three Hundred Twenty Seven"
keft As we move left, each position is 10 times bigger!
From Units, to Tens, to Hundreds

... and ...

As we move right, each position is 10 times smaller. right
From Hundreds, to Tens, to Units


But what if we continue past Units?

What is 10 times smaller than Units?

1/10 ths (Tenths) are!

But we must first write a decimal point,
so we know exactly where the Units position is:
"three hundred twenty seven and four tenths"

And that is a Decimal Number!

Decimal Point

The decimal point is the most important part of a Decimal Number. It is exactly to the right of the Units position. Without it, we would be lost ... and not know what each position meant.

Now we can continue with smaller and smaller values, from tenths, to hundredths, and so on, like in this example:

Large and Small

So, our Decimal System lets us write numbers as large or as small as we want, using the decimal point. Numbers can be placed to the left or right of a decimal point, to indicate values greater than one or less than one.

The number to the left of the decimal point is a whole number (17 for example)
As we move further left, every number place gets 10 times bigger.
The first digit on the right means tenths (1/10).
As we move further right, every number place gets 10 times smaller (one tenth as big).

Definition of Decimal

The word "Decimal" really means "based on 10" (From Latin decima: a tenth part).

We sometimes say "decimal" when we mean anything to do with our numbering system, but a "Decimal Number" usually means there is a Decimal Point.

Ways to think about Decimal Numbers ...

... as a Whole Number Plus Tenths, Hundredths, etc

You could think of a decimal number as a whole number plus tenths, hundredths, etc:

Example 1: What is 2.3 ?

  • On the left side is "2", that is the whole number part.
  • The 3 is in the "tenths" position, meaning "3 tenths", or 3/10
  • So, 2.3 is "2 and 3 tenths"

Example 2: What is 13.76 ?

  • On the left side is "13", that is the whole number part.
  • There are two digits on the right side, the 7 is in the "tenths" position, and the 6 is the "hundredths" position
  • So, 13.76 is "13 and 7 tenths and 6 hundredths"

... as a Decimal Fraction

Or, you could think of a decimal number as a Decimal Fraction.

A Decimal Fraction is a fraction where the denominator (the bottom number) is a number such as 10, 100, 1000, etc (in other words a power of ten)

So "2.3" would look like this:

And "13.76" would look like this:


... as a Whole Number and Decimal Fraction

Or, you could think of a decimal number as a Whole Number plus a Decimal Fraction.

So "2.3" would look like this:
2 and

And "13.76" would look like this:
13 and


Those are all good ways to think of decimal numbers.

Let's learn


A polyhedron is a solid with flat faces (from Greek poly- meaning "many" and -edron meaning "face").

Each flat surface (or "face") is a polygon.

So, to be a polyhedron there should be no curved surfaces.

Examples of Polyhedra:

Triangular Prism Cube Dodecahedron

Common Polyhedra

Platonic Solids

Counting Faces, Vertices and Edges

If you count the number of faces (the flat surfaces), vertices (corner points), and edges of a polyhedron, you can discover an interesting thing:

The number of faces plus the number of vertices minus the number of edges equals 2

This can be written neatly as a little equation:

F + V - E = 2

It is known as the "Polyhedral Formula", and is very useful to make sure you have counted correctly!

Let's try some examples:

This cube has:
  • 6 Faces
  • 8 Vertices (corner points)
  • 12 Edges
F + V - E = 6+8-12 = 2

This prism has:
  • 5 Faces
  • 6 Vertices (corner points)
  • 9 Edges

Let's find the volume of cuboid

Volume of a Cuboid

A cuboid is a 3 dimensional shape.
Therefore to work out the volume we need to know 3 measurements.

Look at this shape.

There are 3 different measurements:

Height, Width, Length

The volume is found using the formula:

Volume = Height × Width × Length

Which is usually shortened to:

V = h × w × l

Or more simply:

V = hwl

In Any Order

It doesn't really matter which one is length, width or height, so long as you multiply all three together.

Example: What is the volume:

The volume is:

4 × 5 × 10 = 200 units3

It also works out the same like this:

10 × 5 × 4 = 200 units3

Saturday, February 20, 2010

Mathematics Link..

--> link di atas memang seronok. Dapat menambahkan pengetahuan dan pembelajaran yang baru.

Multiplication Table

How to Learn
Your life will be a lot easier when you can simply remember the multiplication tables. So ... train your memory! First, use the table above to start putting the answers into your memory.Then use the Math Trainer - Multiplication to train your memory, it is
specially designed to help you memorize the tables.

Use it a few times a day for about 5 minutes each, and you will learn your tables.

Try it now, and then come back and read some more ...

So, the two main ways for you to learn the multiplication table are:
1.) Reading over the table
2.) Exercising using the Math Trainer

But here are some special "tips" to help you even more:

Tip 1: Order Does Not Matter

When you multiply two numbers, it does not matter which isfirst or second, the answer is always the same.
Example: 3×5=15, and 5×3=15
Another Example: 2×9=18, and 9×2=18
In fact, it is like half of the table is a mirror image of the other!
So, don't memorise both "3×5" and "5×3", just memorise that "a 3 and a 5 make 15" when multiplied.
This is very important! It nearly cuts the whole job in half.

In your mind you should think of 3 and 5 "together" making 15.
so you should be thinking something like this:

Tip 2: Learn the Tables in "Chunks"

It is too hard to put the whole table into your memory at once. So, learn it in "chunks" ...

A -->Start by learning the 5 times table.

B -->Then learn up to 9 times 5.

C -->Is the same as B, except the questions are the other way around. Learn it too.

D --> Lastly learn the "6×6 to 9×9" chunk

Then bring it all together by practicing the whole "10 Times Table"
And you have learnt your 10 Times Table!
(We look at the 12x table below)

Some Patterns
There are some patterns which can help you remember:
2× is just doubling the number. The same as adding the number to itself.
2×2=4, 2×3=6, 2×4=8, etc.

So the pattern is 2, 4, 6, 8, 10, 12, 14, 16, 18, 20
(And once you remember those, you also know 3×2, 4×2, 5×2, etc., right?)
5× has a pattern: 5, 10, 15, 20, etc. It always end in either a 0 or a 5.
10× is maybe the easiest of them all ... just put a zero after it
10×2=20, 10×3=30, 10×4=40, etc.
9× has a pattern, too: 9, 18, 27, 36, 45, 54, 63, 72, 81, 90

Now, notice how the "units" place goes down: 9,8,7,6, ...? And at the same time, the "tens" place goes up: 1,2,3,...?

You can use this pattern to prompt your memory this way: the tens place will be 1 less than what you are multiplying by!

Example: 9×7 ... go 1 less than 7, so the tens place is 6, and then remember 63