Ffocws rhifedd : gemau a thaflenni cefnogi gweithgaredd D  /
Williams, Helen.
Qualifications, Curriculum & Assessment Authority for Wales.
Caergybi : Gwasg Taf,
2003.
Argraffiad Saesneg gwreiddiol = Original English edition : Oxford : Rigby, 2002.
Addasiad Cymraeg gan Awdurdod Cymwysterau, Cwricwlwm ac Asesu Cymru = Welsh adaptation by Qualifications, Curriculum and Assessment Authority for Wales.
Numeracy