1. Suppose the number is in column A, the corresponding number is in column B, and the number 2 appears in the table below. I don't know if you are talking about another table, such as SHEET2, or a cell in the same table.
So we must assume that the number 2 is filled in A2 of SHEET2, and then enter the formula in B2 of SHEET2.
=VLOOKUP(A 1，SHEET 1！ A: B, 2,)
Drop-down copy formula
But the number of SHEET 1 must not be repeated, otherwise it will only correspond to the first corresponding row of the same value in the SHEET 1A column.
2. Suppose (the third hypothesis) 2 is filled in the cell C 1, and the formula =VLOOKUP(C 1, A:B, 2,) is entered in the cell D 1.
3.= vlookup (A2, $ b $8: $ d $ 1 1, 3,0) is used for C2, while = vlookup (A2, $ b $12: $ d $15,3. For example, if you put the monthly data in a table and fill in the data every month, you can automatically calculate the above table.