For the 80 column shell you need the file system-configuration which is 232 bytes.
To run Calculator you need mathieeedoubbas.library (4688 bytes), mathieeedoubtrans.library (15728 bytes) and Calculator itself (7996 bytes).
Given that OFS divides the floppy into blocks of 488 bytes each, system-configuration needs one block, mathieeedoubbas.library 10 blocks, mathieeedoubtrans.library 33 blocks and Calculator 17 blocks. Plus a directory block for each entry sums up to 65 blocks or 31720 bytes occupied on the disk.
Directory "df0:" on Friday 13-Jun-14
Calculator 7996 ----rwed Today 17:04:26
mathieeedoubbas.library 4688 ----rw-d Today 17:04:16
mathieeedoubtrans.library 15728 ----rw-d Today 17:04:16
system-configuration 232 ----rwed Today 17:04:39
4 files - 65 blocks used
Mounted disks:
Unit Size Used Free Full Errs Status Name
DF0: 880K 67 1691 3% 0 Read/Write calc