The following series cover all ages and levels. So when ordering books, you will need to source the right level for your child. If in doubt, start with a lower level, then work up. At primary level, a short burst of concentrated effort each morning will be more beneficial than a long slog. But these workbooks and resources should ensure steady progress.
Handwriting
Alphaprints Workbooks 123ABC
Nelson Handwriting Books
Schofield & Sims Writewell Series
Grammar
Schofield & Sims Understanding English series
Spelling and Phonics
Oxford Spelling Workbooks 1-6
Maths
Maths No Problem Books (P1-7)
Schofield & Sims Mental Arithmetic Series
Collins Mental Maths
Bond No Nonsense Maths
Essential Reference Books
Maths
Usborne Junior Illustrated Maths Dictionary
Literacy
Usborne First Grammar and Punctuation
The Usborne Illustrated Thesaurus
Jumpstart Storymaking
Jumpstart literacy