cmac wrote...
I need to make a table that evaluates a number. *

If a number (x) is between (A) and (B), then I have to do a
calculation (C1) If a number is between (B) and (C), then I have to
do a calculation (C2) If a number is between C and D, then I have to
do a calculation (C3) If a number is greater than D, then I have to
do calculation (C4)

And if x <= A?

Brute force,

=IF(x<=A,"impossible",IF(x<=B,C1,IF(x<=C,C2,IF(x<= D,C3,C4))))

More elegant,

=CHOOSE(MATCH(x*0.999999999999999,{-1E300;A;B;C;D}),"impossible",
C1,C2,C3,C4)