Learn how to do simple magic tricks and have them figure it out. Uno works well for us. Random board games from the public library. Some work, some not, but w

Learn how to do simple magic tricks and have them figure it out. Uno works well for us. Random board games from the public library. Some work, some not, but we don't spend money to figure it out. 8 year-old can already play games like Pokémon Trading Card Game. While that's absolutely a money sink, it encourages them to read and do simple math.