Think of a secret number and keep it in your head. Marvo the cat magician shows you some colour cards, one at a time. Look at every number on the card and tap Yes if your number is there, or No if it is not. Then Marvo reads your mind!
The secret: every card has dots on it. Add up the dots on the cards you said Yes to, and you get your number. Tap You guess to try it the other way: Marvo thinks of a number, the bright cards show where it is, and you work it out. Stuck? Tap Hint and the next card to tap glows. Every number you read joins your number collection.