Sums - D4 MINUS D3 EQUALS D5

[Mark]

I am trying to make a spreadsheet for mileage expenses

for example
if D4 is the amount i was paid
and D3 is the amount of fuel i Paid for
I need to know how much is left for wear and tear costs D5

I can not get this sum to work, can you help with the formula?

eg: D4 =100
D3 = 50
D5 needs to automatically work out the difference so D5 = 50.

 

[exoticdisease]

Put this in cell D5:

=sum(d4-d3) or even just =d4-d3

 

[Teethless mama]

It's a "grade three" math

=D4-D3