Formulas in Excel calculate in a blink of an eye. Sometimes you have the needs to see what is happening in your formula calculation. For that you can use the Formula Evaluate function in Excel 2010. On the following example we have a simple formula on cell C1, has you can see on the formula bar.

If you select the cell where the formula is and go to the Formulas tab on your menu bar, go to the Formula Audition group and select the Evaluate Formula option, has shown on the image below. This will open a Evaluate Formula dialog box where you can evaluate your formula.

You have an Evaluate button on the bottom that you can click to calculate the underlined portion of your formula (in this case A1). You can use the Step In and Step Out button to go in detail of the underlined portion of your formula.

You can also evaluate just a portion of your formula instead of the entire formula. For that, on the formula bar, use the mouse to select the portion of the formula that you want to evaluate. In this example, we just want to evaluate the A1+A2 portion of our simple formula.

Then press F9 and Excel will just calculate the portion of the formula that you’ve selected, as shown on the next image.

This will display 257 on the formula bar that corresponds to the sum of A1+A2 cell values. Don’t forget to press ESC to exit the formula after you use this method because if you press Enter, that portion of the formula will stay as the calculated value, in this case, it will keep the 257 value instead of the A1+A2 formula.