Stock Control, SUM IF

[Jamesbil]

Hi,
I'm trying to create a simple stock control sheet.
I have a list of items ordered, I change the cell colour to green when it is made. Yellow is not yet made.
I want to calculate the total of the values in all yellow cells in Col F.

How do I do this?

Thanks

[zbor]

Look at here: https://support.microsoft.com/en-us/kb/2815384

[Jamesbil]

Ok got the first bit done.
Next bit is more complicated.
My range is from col C to AK. Rows 5 to 55

Rows 16, 18, 20, 22 etc Contain quantities
Rows 13, 24, 35 etc contain item name

I have set it so that when there is a number in C18 it shows yellow.
I would like to set it so that if there is a number in C18, C20, C22 then C24 also shows yellow.
I have done it with conditional formatting, Formula is, =C18:C22>0, but I dont want to repeat this hundreds of times for each row and col.

How do I do this?

[Jamesbil]

Thanks. got that done.
Now I need to highlight a cell if it contains a value. So if B1 contains the number "1" (or any number) I want it to show yellow. I also want B12 to show the same colour if there is an entry in B1

How do I do this?