Cut a 3-inch horizontal line across the tennis ball (so when you squeeze the ball, it looks like the tennis ball is opening a mouth). Put the coins (beans or beads can be used as well with older kids) on the table, in front of the child.
First, show the child how to squeeze the ball so it opens its mouth using only one hand (preferably the dominant hand). Then have the child pick up the coins, one coin at a time, using a pincer grasp and “feed” the ball by squeezing it with the other hand and opening its mouth.
To work on finger translation, ask the child to pick up 2-3 coins at one time and “feed” the tennis ball one coin at a time.