The mandi package provides commands for typesetting symbols, expressions, and quantities used in introductory physics and astronomy. Many of the commands are inspired by Matter & Interactions by Ruth Chabay and Bruce Sherwood. Many of the astronomical commands were inspired by my own classroom needs. This package does not do computations. It only provides commands for typesetting. Run mandi.ins through pdfLaTeX to generate files mandi.sty and vdemo.py. Run mandi.dtx through pdfLaTeX to generate mandi.pdf (documentation). I assume a TeX Live 2011 or later distribution is installed.