i don´t know how to put in a formula the action that makes the shortcutkey
F9(gives another number in the cells with the function random)

F9 is the keyboard short cut for "Calc Now" Go to Tools and Options then
the Calculation tab to see this option.

if you want to show a "random" number when you press the F9 - the function
you are looking for is Rand()

"help me please i´m lost" wrote:

i don´t know how to put in a formula the action that makes the shortcutkey
F9(gives another number in the cells with the function random)

i know all that you wrote, but the thing i want to know is how i put that in
a formula for an entire sheet

If you understand VB, you can insert a button and assign the function
"Worksheet.Calculate" to it.

"help me please i´m lost" wrote:

i know all that you wrote, but the thing i want to know is how i put that in
a formula for an entire sheet