Assuming your number is in cell A1, and your "groups" continue down Column A.
In A2 enter:

=MIN($A$1*2-SUM($A$1:A1),1000)

Copy down as far as needed.

HTH,
Elkar


"Ooley" wrote:

I have a number, say 3,450, that I want to subdivide into groups of 1,000
like this:

1000
1000
1000
450

I want this to repeat in as many cells as needed to get down to 0.

Any suggestions?