AbstractNew electronic calculating machines are appearing on the market so rapidly that it is difficult to define criteria with which to assess them. The Hewlett-Packard 35 reviewed in the last issue of this journal(1)set a new standard in size and range of functions offered; this new machine, the Casio fx—l (fx one) is larger (240×315×77.5 mm, 2.3 kg) and operates from mains only but offers a slightly different range of functions and operating features. It should not be necessary to repeat the introductory remarks made in the review of the HP35 except to say that the Casio is able to cope with all the operations of a mechanical machine to an accuracy of 11 significant figures.