Daily activities such as counting forwards and backwards, skip counting, playing games with numbers etc. could be some good practice, however, more specific activities will be sent to you via Seesaw.
Khan Academy - You can sign your child up for Khan Academy which has teaching videos and interactive activities to go with them. It will also track their learning. There are a variety of games and activities not only in maths but in reading, writing and more. Click here for the link to Khan Academy.
Watch Number Blocks - Doubles, Whole numbers, addition and subtraction, odds and evens. Feel free to look at other Number Blocks videos on YouTube or YouTube Kids. Here are some links for you to watch:
Double Trouble with Numberblocks