The paper describes three methods of storing decimal digits, which are extensions of the well-known method of storing binary digits using a cathode-ray-tube store.7 It is shown that one of these methods, which uses ten separate but small elements of the cathode-ray-tube screen, provides the best compromise between speed of operation, digit storing capacity and reliability.A complete serially-controlled cathode-ray-tube store holding 32 words of 8 decimal digits has been operated successfully. The digit period was 40 microsec, and could be conveniently reduced to 30 microsec if desired. These results compare favourably with those for the binary store used in the Manchester University computing machine.In the Appendix it is shown that the preferred decimal system may be derived from a new binary system of storage.