We propose developing a computer ``apprentice system'' to aid researchers and students in addressing the energy, environmental, and economic (EE&E) issues which arise in studies of energy use and energy policy assessment. Much of the task of forming a reasoned opinion about such issues involves finding the relevant numbers for the questions at hand, and then combining them mathematically, to obtain estimates answering the questions posed. Often, the mathematics involved is quite simple (though sometimes tedious), and the resulting estimates are only rough, but capture the basic features of the conclusions sought. Sometimes, it is worthwhile constructing and solving more elaborate mathematical models, whose parameters consist of the same set of known quantities used in the simpler estimates. We believe that both processes, of accessing the basic numbers (the `grist') and of combining them to draw new conclusions (the `mill'), could take less time and effort than now, and could thereby be made appreciably more efficient and productive, through the proposed EE&E\ apprentice system ``E3''. The Apprentice could thus be important both for researchers in the EE&E domain, and also for students and other newcomers to this area, and could form the core of a system which would enhance communication and standardize information among institutions doing work in associated fields.