Take a look at this great Excel formula resource.
Have you explored VLOOKUP capabilities? You may have to shift the columns to start the lookup number followed by the value. In other words A3 will have 1.01 and B3 will be 500.
So set up the table with all lookup values in col. A and then corresponding number in col. B.
On Sheet 2, on cell A5 use =VLOOKUP(lookup number,Sheet1!A3:B50,2,FALSE). If you want to get a perfect match. Or use =VLOOKUP(lookup number, Sheet1!A3:B50,TRUE) – will get the number equal to less than matching number.