ClarisWorks requires at least System 6.0.5 and 1 MB of RAM. Under System 7, like everything else, it requires 2 MB of RAM.
The manuals include installation instructions appropriate for floppy-based Macs and hard drive systems. The application itself occupies 562K on disk. The application memory partition defaults to 900K, but it can be set as low as 768K. ClarisWorks can work easily on a Mac with two 800K floppies, and it's possible with some finagling to place the application on a single 800K floppy disk along with a bootable System 6 or a bootable high-density System 7 disk. One must do without the spelling, file translator, and thesaurus functions under these configurations, but these can be kept on separate floppy disks. I would still recommend a Plus-level machine with at least 2.5 MB of RAM and a hard drive as the preferred entry point for using ClarisWorks, but if you're stuck with something less, it's a usable and attractive option. The communications documents require a hard drive, however, since they require installation of the Mac Communications toolbox under System 6.