The Cbeebies programme 'Numberblocks' is great for helping your little ones develop their maths skills.
The NCETM have produced these powerpoints to support parents to use Numberblocks at home:
Children also have access to Numbots which is an online game that rehearses basic number skills. It can also be downloaded as an app on Apple or android devices. Your child should have a log-in. Please ask their teacher if you don't know it.