This might be one of the best tricks ever invented for children magicians. That's also why the trick is widely recognized as of the classics of magic.

You show a big dice made of wood and a box with two rooms. You place the dice in of the boxes rooms and close the four doors. After a few magic words, you open one of the doors and show the audience that the dice is gone. The children yell that it is in the other room, but you close the door again, tilt the box a little and open the door to the other room, to show that it's not there either. You continue like that, while the children get increasingly annoyed. They can not only see that you're tilting the box, but also hear the sound of the dice sliding back and forth. 

At last - after a lot of fun - the children finally convince you to open all four doors at once... To their surprise, the dice has actually dissaperead and is not to be found inside the box. Then for the final touch, you pull the dice out of your hat, while the audience roar with laughter. 

You receive an elegant dice box that is the most beautiful we have ever had in stock. A routine that is sure to be a hit at your next children show, because the kids constantly think that they've figured it out, but still end up being surprised in the end.