Dart Scoring table

[LCBO]

I've made an auto dart scoring sheet. In column A I have the dart score
input, in column B it auto subtracts that score from the set amount. The
problem is if I use say 301 as the start score in column A column B shows 301
thru all of row B. Is there a way to hide the 301 in column B until a score
is posted in column A?

 

[LCBO]

Thanks John
I input =IF(A2="", "", $A$1-A2) into B2, 301 into A1. Put in 100 in A2 and
got 201 in B2...perfect! But when I input =IF(A3="", "", $A$1-A3) into B3 and
100 in A3 I get 201 again. It isn't subtracting from 201 which should be 101
in B3

 

[Gary Keramidas]

you can put this in B2 and copy down

=IF(A2="","",$A$1-SUM($A$2:$A2))

but i'm not sure what you want when you get to negative numbers because i don't
play darts

 

[LCBO]

Nope still didn't work John but thanks.
Gary's did and ty much for the help!!