Learning maths using screen-based resources is a great way to engage children – especially for Key Stage Maths
That said, it is very important for children to put actual pencil (or pen) to paper instead of just using a mouse.
Screen-based learning (e.g. BBC Bite-size) is useful for a limited period of time (at Key Stage Maths we recommend 30 minutes max per session) – but should not be considered a substitute for sitting down with revision books and actually working out problems.
Furthermore, no amount of reading alone will help secure numeracy and recall.
Spend a higher proportion of time working things out on paper
A child should work out addition, subtraction, division and multiplication on paper as they would in a SAT test or entrance exam.
Similarly, for science subjects there is no substitute for answering questions on paper – writing the very sentences and using the very words for which they can score points in tests.