Place Value
Our Number System is based on ten.
Using only ten symbols (called Digits) we can write any number.
The Ten Digits
The Digits we use today are called "HinduArabic Numerals" and look like these:
0
1 2 3 4 5 6 7 8 9
You can use these on their own to count up to 9.
Ten Or More ...
When we have more than 9 items, we start another column  the "tens" column  and we write down
how many "tens" we have, followed by how many ones (called "units"):
The Number "12"
So we know that we have 1 Ten and 2 Ones, which makes 12.
This could also be written as 1 × 10 + 2 × 1.
Example: "35" means 3 Tens and 5 Units, which is also 3 × 10 + 5 × 1
A Hundred Or More ...
When we have more than 99 items, we start another column  the "hundreds" column. Now we need
to show how many hundreds, tens and units:
The Number 143
So we know that we have 1 Hundred, 4 Tens and 3 Ones
This could also be written as 1 × 100 + 4 × 10 + 3 × 1.
Example: "369" means 3 Hundreds, 6 Tens and 9 Units, which is also 3×100 + 6×10 + 9×1
And So On ...
So, each time we need to show a bigger number we just add one column to the left and we know it is always
10 times bigger than than the column on its right.
each new column on the left is ten times bigger
So, where we PLACE a digit is important!
Zero
What if we have 1 Ten, but no Units? We show that we have no units by using a zero there:
Tens 
Units 
1 
0 


The Number "10"
We have to put a zero, or "10" would look like "1".
We use the same thing to show zero tens, hundreds, etc
Example: "203" means 2 Hundreds, Zero Tens and 3 Units.
Names for Each Column
These are the names of each column:
Millions 
HundredThousands 
TenThousands 
Thousands 
Hundreds 
Tens 
Units 
(For bigger amounts, see Metric Numbers)
Example:
In a placevalue table write down the number eleven thousand, three hundred and twenty seven:
TenThousands 
Thousands 
Hundreds 
Tens 
Units 
1 
1 
3 
2 
7 
