Hello everybody.
I wanna ask, if anyone could give me good effects, books, or ideas about forcing a 5-digit number ..
the kind of effects I'm looking for in the example below ..
for example >>> 3 spectator each writes a number >>> when added together the result is a 5-digit number that is predicted (the result number is pre-known by the performer)

The effect you are exploring already exists, usually under the name of "Add-a-Number." The major magic shops sell several options. You can probably "search" (above right) and find each of the options discussed on threads here at the Café.

George