Basic Excel Math Formulas: Add/Subtract/Multiply/Divide
How to reference cells (use their value) with Excel formulas
The following formula uses the value found in cell A5, and will change if we change the value of A5 (note that this is a subtraction formula):
Enter a value into cell A5 (for example, 3). Then enter '=10-A5' (without the quotes) as the formula in another cell.
So, if we change the value found in A5 to 9 instead of 3, the formula will automatically update to show the new result (which is 1). For example:
The following Formula refers to cell B5 as well as to cell A5 and its result will change if we change the value of either cells:
Up until now we've seen examples of formulas that use the addition ('+'), subtraction ('-') and multiplication ('*') operators.
There's an additional operator we need to cover in order to complete our tour of the basic math formulas in excel - the division ('/').
The following formula shows how to use the division operators to divide the value in A7 by the number in B7:
Note that if you put 0 in the divider cell (in this case, B7), you will get an error result, as dividing by zero does not result in a valid mathematical answer.