These days, we have become so used to computers, mobile devices and hand held or calculators for our day-to-day activities, so much so that some of us may have forgotten how we got by doing the more complex calculations back in those days where the hand held calculator did not exist. I myself had almost forgotten this myself until I dug up a book which accompanied me during my secondary school days and when I sat for my “O” level examinations: a book of Logarithmic Tables or the “Log Book” as we used to refer to it in school. I am not sure how long they were used for, but by the time my sister was sitting for her “O” level examinations, she had already been using a hand-held calculator to help with the more complex multiplications, divisions, and trigonometric calculations.
Front and Back Covers of the "Log Book" that I used.
I think most of us back then had a wonderful time with it … some probably used it to sneak in mathematical formula for the exams. The Log Book actually helped many of us to appreciate some of the mathematical concepts better such as the use of logarithms and interpolation (of which we had to master to be able to successfully make use of the Log Book), where these days we are used to having numbers appear at the touch of a button without really putting much thought into it.
Contents of the Log Book.
Instructions on how to use the Log Book.
Complex multiplications (or divisions) could be done by converting numbers into a logarithm, being the exponent that a base number is raised to give the number. This simplified multiplications and divisions as the exponent could then be added or subtracted and the resultant being reconverted back (antilogarithm) to a number. There were also tables for sines, cosines and tangents as well as for square roots and hyperbolic functions in the Log Book. I know it sounds like a tedious process but it made a world of difference when access to a calculator was limited.
Table of Logarithms.
Table of Antilogarithms.
Table of Logarithms of Sines.
Table of Cosines.
Table of Square Roots.
The Long and Winding Road 
Do u have copies of the 10-Year series? We used to get them from SS Mubarak (I think) down at Bras Basah Road. Are you aware next to SJi there was this lane and an Anthonian Bookstore (or was it some secondhand store???) that sold highly prized XXX-rated German porno magazines? I dont mean Anthonian sold it but a stall next to Anthonian (I think)
Peter, that was something I was quick to get rid of as soon as I got my ‘O’ level results … I did have a few … they were sold at most of the bookshops along Bras Basah – and when I went to school there, most were displayed at the front of the bookshops along with study guides for literature and some other subjects … I am not sure which lane you meant Peter … could have been Beng Swee Place? Don’t remember there being a bookshop there though.
Remember “Bee Loh”, the shop selling photography stuff, and the “Camera Hospital” next to it. It was the pre-digital camera era.
Thanks for your comments FS, Bee Loh would have been at Bras Basah Road if my memory serves me correctly? When I went to school in the area the Camera Hospital was along Bencoolen Street – the Camera Hospital is still around in nearby Sunshine Plaza – I understand it is now run by the son of the original shop owner. 🙂