# Formula basics, sum, count, average, cell reference

When you input a “=“ as the first character in a cell, the app will enter “formula input mode“, you can input a formula follow by the character “=“, such as “=1+2“, then the cell will show “3“ as the result.

You can reference another cell in the formula, for example, you input “=A3+1“, if cell A3‘s value is 5, then the result will show “6“.

When “formula input mode“, you tap another cell always mean input the cell‘s reference into current formula.

If you want to quit formula input mode, click the finish button (the most right button on the bar above the soft keyboard).

You can use some functions in the formula , such as “sum“,“avg“,“count“, etc. their function are same as Microsoft Excel.