Excel's built-in SUM function will automatically exclude blank cells from its calculation.

However, there are ways to include blank cells if needed:

1. SUM with IF statement:

This method uses an IF statement within the SUM function to check for blank cells and assign a value (often 0) to them before summing.

Example:

```excel
=SUM(IF(A1:A10="",0,A1:A10))
```

This formula checks each cell in A1:A10. If a cell is blank (""), it assigns 0; otherwise, it uses the cell's actual value. Finally, it sums all the values (including zeros for blank cells).

2. SUMIFS with wildcard ("*"):

This method uses SUMIFS with a wildcard criterion to essentially include all cells in the range.

Example:

```excel
=SUMIFS(A1:A10,"*",B1:B10,">0") (* assumes another column B with criteria)
```

Here, SUMIFS sums values in A1:A10 where the corresponding values in B1:B10 are greater than 0. Since the first criteria uses "*" (wildcard), it effectively includes all cells in A1:A10 regardless of content (blank or value).