Ordering and sequencing are all prerequisites to simple addition and subtraction. Incorporate these skills into daily routines. When your child is straightening up her room, make a game out of it by having her pick up her toys according to size, putting the biggest one away first and so on until the smallest is put away last. This game is a good time to point out that when things are the same size, they are equal. Visual guessing, or estimating, is a lifelong skill needed when measuring isn't possible. Your child will learn that her eyes are a source of information.