When we add 1,000 to a number less than a thousand, we must place a 1 in the thousands column.

 

Here is the number 623 shown on an abacus.

 

Notice that the abacus says units. Units are another word for ones.

  

                 

 

When we add 1,000 to this number, we add an extra column to the left.

This is the thousands column.

We get the number 1,623.

 

 

623 + 1,000 = 1,623

 

Don't forget zeros!

 

Here is 52 shown on an abacus.

 

 

When we add 1,000, we get:

 

 

Notice that there are no hundreds. 

This number is 1,052.

52 + 1,000 = 1,052

 

Putting a zero in the hundreds column is really important to act as a place holder. Without the zero, the number we would have got would have been 152, which is very different to 1,052, isn't it!