Are you talking about stocks or bonds?
If stocks, here is a link to find the current value of those shares, which may have split over the years. If you have the certificate, you know the approximate date of purchase and can use this calculator to see if the original 27 shares have subsequently split.
Since you specifically mentioned the number of shares, I doubt you are holding bonds. Please write back if you actually hold bonds, and include the entire name of the bond, interest rate and date of maturity that is written on the certificate.