Problem calculating time

Hello,

I'm having a little problem calculating time.

I have entered the following informating in an Excel sheet.

A1 = 12:00:00
A2 = 12:00:00
A3 = 1:00:00
A4 = 0:45:00

In cel A6 these values are added, with the formula
=SUM(A1:A4).
So the value 25:45:00 is displayed in cel A6.

All cells are defined as "Time" (Hours:Minutes:Seconds)

What I want to do next, is the following.

I would like the time being displayed as decimal values in cel A8.
So 25:45:00 should become 25,75 in decimal notation.

Can anyone help me how to do this ?

Thanks.... :-)

Frits Jager