The latest version of Multiplan is Multiplan 1.1, and it doesn't work on
the Macintosh Classic. Multiplan 1.1 has not been sold in the U.S. since
1986.
Microsoft Technical Support told us that the latest version of System
Software that Multiplan 1.1 was tested with is System Software 2.0 which
used System 4.1 and Finder 5.5. Microsoft no longer supports Multiplan and
suggests upgrading to Excel.