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Take a look at the interactivity below.
Try it a few times.
Can you work out what's going on?
Can you explain how the machine 'guesses' your picture correctly?
You may also be interested in the other problems in our Mathematical Wizardry Feature.
Choose two digits and arrange them to make two double-digit numbers. Now add your double-digit numbers. Now add your single digit numbers. Divide your double-digit answer by your single-digit answer. Try lots of examples. What happens? Can you explain it?
Follow the clues to find the mystery number.
What do the digits in the number fifteen add up to? How many other numbers have digits with the same total but no zeros?