Practice number recognition and counting. Here a couple of ideas, there are lots more on Pintrest if you need some. Give you child a number written on paper, see if they can recognise it then count out the correct amount of items (you can use cereals, toy or anything you can put you hands on quickly). Another favourite in our house is to label some buckets or containers with numbers, ask your child to throw balls, beanbags or balled up socks into the correct container when you call a number. You can also challenge your children to throw the correct amount of balls into the bucket e.g. 4 balls into the bucket labeled 4.