Tables of Logarithms of Numbers and of Sines and Tangents for Every Ten Seconds of the Quadrant, With Other Useful Tables: By Elias Loomis

This is, of course, a facsimile of an old, scholarly book c.1848. With the copying process, you will notice that ink spots have been reproduced on a few pages meaning that there are some figures that are illegible. And you will need a magnifying glass (or superb eyesight) as numbers are small. The figures are nonetheless clear, and this is a treasure of a useful book.

If you want to remain numerate, then throw away your calculator and buy this book, it contains all you need to keep that unused brain ticking over. A useful teaching aid too, containing very good examples of practical calculations. I scoured a few book shops trying to find a similar reference book, but not satisfied with the choice. Several good books are available from Amazon, this certainly is the most comprehensive.