Adding 1000 and 100

Date: 11/23/97 at 21:40:13
From: Julia Collins
Subject: Addition

I am really wondering how to add 1000 + 100. I have tried to add them 
together like this:

               1000
             +100
              -----------
                 ? 

Can you help me?

Date: 11/24/97 at 13:19:00
From: Doctor Mike
Subject: Re: Addition

Dear Julia,
   
You line them up vertically so the far right digit of the bottom 
number is lined up with the far right digit of the top number.  

It will look like this : 
   
             1000
            + 100
           -------
             1100 
  
You read this answer either as "one thousand, one hundred" or
as "eleven hundred."  Here is another example : 
    
              1024
             + 210
            -------
              1234 
  
What I have done here is to add together the two digits in each 
vertical pair of numbers. 

Each position in a number is often called a "PLACE." For instance, the 
position that has a 2 in the top number, a 1 in the bottom number, and 
a 3 in the answer is called the "tens place," because whatever is 
there means a certain number of tens.  When I add 2 and 1 to get 3, 
what this means is that I am adding 2 tens and 1 ten to get 3 tens.  
That is the same as adding 20 and 10 to get 30.  

You will learn much more about number places as you continue in 
school.  

I will end by telling you about all the places in the answer number 
1234.   
    
   In the number 1234, ... 
 
   The "1" is in the "thousands" place, and it means     1000
   The "2" is in the "hundreds" place, and it means       200
   The "3" is in the "tens" place, and it means            30
   The "4" is in the "ones" place, and it means             4
   Add all those together, ...                          ------ 
     ... and you get                                     1234 
   
I hope this helps.  Write back to us if you have another question.
                    
-Doctor Mike,  The Math Forum
 Check out our web site!  http://mathforum.org/dr.math/