The checkerboard worksheet is numbered so that the columns beginning at the left hand side of the checkerboard are represented by letters and the rows of the checkerboard beginning at the upper left side are represented by numbers. Any cell can be defined or identified by the combination of a letter or number so that the cell in the upper left hand corner is referred to as A1 while the cell in the third row, second column is referred to as B3. A formula might be the sum of the preceding three cells. If one wanted to change the numbers in one or more cells, simply typing in the desired number when the cursor is positioned on a particular cell and pressing the enter key would result in the new sum or changed sum in cell D4. Thus, the key feature of a spreadsheet is that you can change one or more of the values or numbers in a cell, and the rest of the spreadsheet is automatically recalculated.
All spreadsheets work in essentially the same basic manner.
The operations on the numbers in the different cells can be complex with substantial involved formulas. Formulas are present in most programs for calculating interest functions, present values and other financial information. It is even possible to have dates entered in cells and calculate the number of days between the current date and a fixed date. That resulting number can be used in another formula for further calculations. The spreadsheet is designed for simplifying repetitive tasks, so that it is not necessary to rewrite similar formulas in each column.