How many necklaces can you make that fit the rule? How do you know you've got them all?
This big box multiplies anything that goes inside it by the same number. If you know the numbers that come out, what multiplication might be going on in the box?
Ram divided 15 pennies among four small bags. He could then pay any sum of money from 1p to 15p without opening any bag. How many pennies did Ram put in each bag?
How could you arrange at least two dice in a stack so that the total of the visible spots is 18?