It was advertised as offering logs, trig, and true scientific notation over a 200-decade range and Sinclair claimed that these were features only available on machines costing £100 or more (at the time of this claim in late 1974 the Scientific was £32.35 built and £19.95 as a kit).

Like its cousin, the basic Cambridge, the Scientific was truly a marvel of miniturisation.  At the time no other calculator came close to having so much power in such a small package and it was a long time before one arrived that did.

Of course, there were bad points.  Whereas the Hewlett Packard HP35 was a fantastic piece of engineering, the Sinclair was fragile and prone to failure of components.  The on/off switch would eventually break (due to wear of the simple mechanism) and sometimes accidental double digit entry happened.

Like all the other Cambridge machines, the Scientific is a difficult collectable to find.  It does seem to turn up more often that the other models, however, which leads us to believe that it was either the biggest seller of the range or that it was kept for longer by faithful users.  Or both!

As always with Sinclair calculators, if you see one and it's cheap (£15 or less) then snap it up.  If you really want a pristine one you either have to be lucky or pay more.