Toss The Snowball is an easy game to set up and can be played with all ages (as young as 2) and numbers.
You will need:
A large basket
5 scrunched up balls of paper
A small prize
The children stand on a line and must throw their paper snowballs into the basket. Vary the distance they stand from the basket according to the age of the child. The child who gets the most items in the basket wins.
If you have a large number of kids to accommodate, play in teams. Use a basket for each team and 3 snowballs per person. The team with the most snowballs in their basket when everyone has had a turn wins.
Instead of a basket, you could also make a large snowman figure out of cardboard (get the kids to decorate it and add a real scarf and hat if you like). Cut out a hole in his tummy - sized appropriately for the children - and prop him up against the wall as a target.