i have created a balance sheet with this formula to calculate the remaining
balance

=SUM(E5-D6+C6)

However this leaves the value from the cell the calculation was taken from i.e
if cell E5 returns a value of 200 the cell E6 returns the same value. How
can i make cell E6 return a 0 value untill data is added to either column's
"C or D"

I hope this is ok to understand.