Blwch yn cynnwys 20 pecyn o gêmau = Box contains 20 packs of games.
Gemau melyn : casgliad o gemau mathemategol i gyd-fynd â gwaith Mathemateg Cynradd Caergrawnt, modwl 5. ISBN 185787093X. Published by Canolfan Astudiaethau Iaith in 1994. Publication and catalogue information, links to buy online and reader comments.