Writing Excel formulas is a little different than the way it is done in mathematics class. All Excel formulas start with an equal sign (=), that is, the equal sign always goes in that cell where you want the answer to appear from the formula. Therefore, the equal sign informs Excel that this is a formula not just a name or number. Let us start with writing Excel Formulas.
The Excel formula looks like
= 3 + 2rather than
3+2 =Writing Excel Formulas and Cell References in MS Excel
The example of a formula has one drawback. If you want to change the number being calculated (3, and 2), you need to edit it or re-write the formula. A better way is to write formulas in such a way that you can change the numbers without changing or re-writing the formulas themselves. To do this, cell references are used, which tells Excel that data/ numbers are located in a cell. Therefore a cell’s location/ reference in the spreadsheet is referred to as its cell reference.
To find a cell reference, simply click the cell of which you need cell reference, and from NAME BOX (shown in the figure below), see the text, such as F2.
F2 represents the cell in the $F$ column (horizontal position) and row 2 (vertical position). It means cell reference can also be found by reading the column heading (at the topmost position) of the cells and row number (at the leftmost position). Therefore, cell reference is a combination of the column letter and row number such as A1, B2, Z5, and A106, etc. For the previous formula example, instead of writing = 3 + 2 in cell suppose (C1), follow this way of cell reference and formula writing:
In cell A1 write 3, and in cell B2 write 2. In the C1 cell write the formula such as,
= A1 + A2
Note that there is no gap between A & 1 and A & 2, they are simply A1 and A2. See the diagram for a clear understanding.
Updating/ Writing Excel Formulas
Upon wrong cell references in the Excel formula, the results from the formula will be automatically updated, whenever the data value in relevant cells is changed. For example, if you want to change data in cell A1 to 8 instead of 3, you only need to change the content of A1. The result of the formula in cell C1 will automatically be updated after the updation of the data value in A1 or B1.
Note that the formula will not change because the cell references are being used instead of data values or numbers.
Read more about Creating Formulas in MS Excel and Operator Order of Precedence