"sparky24" wrote:
i used the formula
(MATCH(B7,{-1E300,1,11,21,31,41,51,61,71,81,91})-1)*1.5
[....]
I do not understand how the formula works but not to
worry, at least it does what i was wanting to achieve,

It is unwise to use a formula without understanding it. If you understand
the LOOKUP expression that you used originally, you should understand the
MATCH expression after reading the Help page.

Without a 3rd parameter (defaults to 1), MATCH returns the index (1 to n) of
the value in the array {-1E300,1,...,91} that B7 is equal to or that is the
largest value less than B7.

Thus, if B7 is empty or less than 1, MATCH returns 1 because B7
matches -1E300. If B7 is 1 or more but less than 11, MATCH returns 2
because B7 matches 1. If B7 is 11 or more but less than 21, MATCH returns 3
because B7 matches 11. Et cetera.

But your original expression returned 1 if B7 matches 1, 2 if B7 matches 11,
etc. And I added: 0 if B7 is empty or less than 1.

Therefore, we must reduce MATCH by 1. Thus, MATCH(...)-1.

Of course, multiplying 1.5 comes from your original formula. Thus,
(MATCH(...)-1)*1.5.