Dummy coins (6), plus conversion chart, to help people learn the new decimal coinage, produced by Robert Gibson and Sons, Ltd, 1968. Plastic coins and conversion chart for British decimalisation
Kelvin Measurement of Ability in Arithmetic Test material, comprises: 1 test booklet, developed by C.M. Fleming, published by Gibson and Sons, Glasgow Ltd., Glasgow, n.d. Kelvin Measurement of Ability in Arithmetic Test material