a) For each combination you can give pronunciations.
Aa=ah "as in father" as in Aaron,
ab=æb, as in nab, eyb as in babe ...,
ac excepting ch=æk as in act, eys as in ace ...
up to az, then go on to ba...
b) For the two letter shapes, you can give the exercise of writing them together.
Mathematics: 0 is no number. Numbers are multiples of one.
Roman numerals are very fine for learning basic arithmetic.
I, II, III, IIII, V, VI, VII, VIII, VIIII, X ... you may train the child to use right hand fingers except thumb for Is, right hand thumb for V, left hand fingers except thumb for Xs and left hand thumb for L:
Same goes for Xs and L, Cs and D and D+D=M./HGL
*Extant. Does not include for instance "bk" except for Abkhasian or "bz" or "kb" except for an Arab word.