5 riddles

Numbers

These number riddles turn on patterns, sums and sequences. Some ask for a mystery number from a few clues, others for the next term in a sequence, a weight on a set of scales or the fewest tokens to pay a total. Plain arithmetic is enough. Each riddle has a hint, the answer and a short explanation, from Easy up to Genius.

Biggest Roman Number Video
Easy Numbers

Biggest Roman Number

A melon weighs 2 kg plus one third of its own weight. How much does the melon weigh?

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Easy Numbers

The Melon

Stack the Stones Picture
Easy Numbers

Stack the Stones

What comes next? 2, 6, 12, 20, 30, ?

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Easy Numbers

Growing Gaps

Join the Dots Video
Easy Numbers

Join the Dots