Rules of the crossnumber
Rules
- The digits 0 to 9 (inclusive) each appear exactly once in every row and column of the completed crossnumber.
- There is only one solution to the completed crossnumber. Solvers may wish to use the OEIS, Python, Microsoft Encarta, etc to (for example) obtain a list of prime numbers, but no programming should be necessary to solve the puzzle. As usual, no entries begin with 0.
- One randomly selected correct answer will win a £100 Maths Gear goody bag, including non-transitive dice, a Festival of the Spoken Nerd DVD, and much, much more. Three randomly selected runners up will win a Chalkdust T-shirt. Maths Gear is a website that sells nerdy things worldwide, with free UK shipping.
- To enter, submit the the digits in the row marked by arrows (in order) using this form by 18 August 2026. Only one entry per person will be accepted. Winners will be notified by email and announced in issue 24.
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