SQL Server Check for IsNull and for Zero

Question

I have the following:

set @SomeVariable = @AnotherVariable/isnull(@VariableEqualToZero,1) - 1 

If @VariableEqualToZero is null it substitutes t

Answer 1

set @SomeVariable = @AnotherVariable /
(case when isnull(@VariableEqualToZero, 0) = 0 then 1 else
@VariableEqualToZero end) - 1