I've got a Google spreadsheet that looks like this:

     Start time  |    End Time   |  Time difference
    -------------+---------------+-----------------
        11:30:00 |    12:45:00   |     1,25     
    -------------+---------------+-----------------
        09:20:00 |    10:30:00   |  
        11:35:00 |    12:00:00   |    #VALUE!
    -------------+---------------+-----------------


In the 3rd column, I have a formula that calculates the difference in decimal number. 1st row works - can I make it work with the 2nd row without splitting the cell?

This is the error I get when I hover over `#VALUE`:
>Error Function MINUS parameter 1 expects number values. But '10:30:00 12:00:00' is text and cannot be coerced to a number. 

The formula is `=(D26-C26)*24`, where C26 and D26 are formatted as time, E column is formatted as a number.