Can you add a (hidden) helper column? That column would do essentially just
what you said: pick up the new value in column A or continue the old value
is column A is blank. In C1, =A1. In C2, =if(isblank(a2),c1,a2). In D1,
=B1*C1 and in D2, =B2*C2. Then just copy down the formulas in C2:D2 to
complete your table.
--Bruce

"Angie A." wrote:

Example

A B C
7 4 =$A$1*B1
5 =$A$1*B2
6 =$A$1*B3
3 1 =$A$4*B4
4 =$A$4*B5

Isn't there a way to tell Excel to always multiply A*B, without using the
$A$? The reason I ask is we have hundreds of sections with new A values and
I don't want to put a new $$ formula in for each section. I was thinking of
something along the lines of A*B, if A=blank use last A value- but I can't
find any examples of this.