Hi Anand,
I don't know which column contains the numbers as text. For argument's
sake say the affected column is column A, then in row 1 of any spare
empty column just type the formula =VALUE(A1), then fill down to be
level with the last nonblank cell in the affected column. Select this
column of VALUEs then copy then select the top cell of column A and
Paste Special Values. Then delete the column of VALUEs.

That should convert the numbers as text to normal numbers.

Ken Johnson