37 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.

Two Candles: Twice as Tall Video
Genius Numbers

Two Candles: Twice as Tall

Two Candles: 32 cm and 22 cm Video
Expert Numbers

Two Candles: 32 cm and 22 cm

How Many Routes: 3 × 2 Grid Video
Medium Numbers

How Many Routes: 3 × 2 Grid

Mirror Clock: The Long Wait Video
Expert Numbers

Mirror Clock: The Long Wait

Roman Subtraction Video
Medium Numbers

Roman Subtraction

Longest Roman Numeral Video
Genius Numbers

Longest Roman Numeral

Mirror Clock: 13:31 Video
Hard Numbers

Mirror Clock: 13:31

How Many Routes: One Cone Video
Hard Numbers

How Many Routes: One Cone

How Many Routes: 2 × 2 Grid Video
Medium Numbers

How Many Routes: 2 × 2 Grid

Two Candles: 12 cm and 8 cm Video
Medium Numbers

Two Candles: 12 cm and 8 cm

Biggest Roman Number Video
Easy Numbers

Biggest Roman Number

Longest Roman Year Video
Hard Numbers

Longest Roman Year

Two Candles: 20 cm and 15 cm Video
Hard Numbers

Two Candles: 20 cm and 15 cm

How Many Routes: Pass the Lantern Video
Genius Numbers

How Many Routes: Pass the Lantern

Hands Apart: 9:45 Video
Genius Numbers

Hands Apart: 9:45

Hands Apart: 6:30 Video
Medium Numbers

Hands Apart: 6:30

Hands Apart: 2:20 Video
Expert Numbers

Hands Apart: 2:20

Hands Apart: 3:30 Video
Hard Numbers

Hands Apart: 3:30

Mirror Odometer: 15951 Video
Medium Numbers

Mirror Odometer: 15951

Mirror Odometer: 29992 Video
Medium Numbers

Mirror Odometer: 29992

Fewest Tokens: Pay 6 Video
Medium Numbers

Fewest Tokens: Pay 6

Fewest Tokens: Pay 24 Video
Genius Numbers

Fewest Tokens: Pay 24

Fewest Tokens: Pay 11 Video
Hard Numbers

Fewest Tokens: Pay 11

Fewest Tokens: Pay 18 Video
Hard Numbers

Fewest Tokens: Pay 18