To autofill a series of values in Excel 2010 using only the keyboard, you can use the Fill Down command. First, select the cell that contains the value you want to fill down. Then, press the Ctrl key and the D key simultaneously. This will copy the contents and format of the topmost cell of a selected range into the cells below. Alternatively, you can use the AutoFill feature in Excel to quickly fill a series of cells with a pattern. To use AutoFill, select the cell that contains the pattern you want to fill, then drag the fill handle (the small square in the bottom-right corner of the cell) over the cells you want to fill. Excel will automatically fill the cells with the pattern, adjusting the values as necessary.