Routledge's decimal ready reckoner: with all computations from 1/2p to £2.0.0.0, and 40 other values of special importance for metrication conversions. Decimal ready reckoner. Metric system Conversion tables. Ready-reckoners. QC94 .R67 511.1083 ROD London, Routledge & K. Paul, 1969. 1969. 1969 Text [454] p. eng