Example:
VLOOKUP(10003, A2:B26, 2, FALSE)
Syntax:
VLOOKUP(search_key, range, index, [is_sorted])

 - search_key - The value to search for. For example, 42, "Cats", or I24.
 - range - The range to consider for the search.The first column in the
            range is searched for the key specified in search_key.
 - index - The column index of the value to be returned, where the first
             column in range is numbered 1.
            Note: If index is not between 1 and the number of columns in
                  range, #VALUE! is returned.
 - is_sorted - [TRUE by default] - Indicates whether the column to be
                 searched (the first column of the specified range) is sorted.
                FALSE is recommended in most cases.
                Note: It’s recommended to set is_sorted to FALSE.
                    If set to FALSE, an exact match is returned.
                    If there are multiple matching values, the content of the
                    cell corresponding to the first value found is returned,
                    and #N/A is returned if no such value is found.
                    If is_sorted is TRUE or omitted, the nearest match
                    (less than or equal to the search key) is returned.
                    If all values in the search column are greater than the
                    search key, #N/A is returned.