Prize crossnumber, Issue 07

by Chalkdust. Published on 12 March 2018.

Our original prize crossnumber is featured on pages 52 and 53 of Issue 07.

Download Crossnumber #7 as a PDF, or read on!
Submit your answer

Clarification: Added “non-zero” to clues 10A, 19D.
Clarification: For 20D, 0 is not a factor of any number, so the number contains no 0s.

Rules

Although many of the clues have multiple answers, there is only one solution to the completed crossnumber. As usual, no numbers begin with 0. Use of Python, OEIS, Wikipedia, etc. is advised for some of the clues.
One randomly selected correct answer will win a £100 Maths Gear goody bag. Three randomly selected runners up will win a Chalkdust t-shirt. The prizes have been provided by Maths Gear, a website that sells nerdy things worldwide, with free UK shipping. Find out more at mathsgear.co.uk
To enter, submit the sum of the across clues via this form by 1 August 2018. Only one entry per person will be accepted. Winners will be notified by email and announced on our blog by 19 August 2018.

Continue reading →

Prize crossnumber, Issue 06

by Chalkdust. Published on 18 October 2017.

Our original prize crossnumber is featured on pages 52 and 53 of Issue 06.

Download Crossnumber #6 as a PDF, or read on!
Submit your answer

Correction: The pdf was incorrect and 5D did not match the clues below. This has now been fixed.
Clarification: Added brackets to 29A and 34D to reduce ambiguity.

Rules

Although many of the clues have multiple answers, there is only one solution to the completed crossnumber. As usual, no numbers begin with 0. Use of Python, OEIS, Wikipedia, etc. is advised for some of the clues.
One randomly selected correct answer will win a £100 Maths Gear goody bag. Three randomly selected runners up will win a Chalkdust t-shirt. The prizes have been provided by Maths Gear, a website that sells nerdy things worldwide, with free UK shipping. Find out more at mathsgear.co.uk
To enter, submit the sum of the across clues via this form by 8 January 2018. Only one entry per person will be accepted. Winners will be notified by email and announced on our blog by 22 January 2018.

Continue reading →

Prize crossnumber, Issue 05

by Chalkdust. Published on 6 March 2017.

Our original prize crossnumber is featured on pages 58 and 59 of Issue 05.

Download Crossnumber #5 as a PDF, or read on!
Submit your answer

Rules

Although many of the clues have multiple answers, there is only one solution to the completed crossnumber. As usual, no numbers begin with 0. Use of Python, OEIS, Wikipedia, etc. is advised for some of the clues.
One randomly selected correct answer will win a £100 Maths Gear goody bag. Three randomly selected runners up will win a Chalkdust t-shirt. The prizes have been provided by Maths Gear, a website that sells nerdy things worldwide, with free UK shipping. Find out more at mathsgear.co.uk
To enter, submit the sum of the across clues via this form by 22 July 2017. Only one entry per person will be accepted. Winners will be notified by email and announced on our blog by 30 July 2017.

Continue reading →

Prize crossnumber, Issue 04

by Chalkdust. Published on 3 October 2016.

Our original prize crossnumber is featured on pages 48 and 49 of Issue 04.

Download Crossnumber #4 as a PDF, or read on!
~~Submit your answer~~ This competition has now ended.

Rules

Although many of the clues have multiple answers, there is only one solution to the completed crossnumber. As usual, no numbers begin with 0. Use of Python, OEIS, Wikipedia, etc. is advised for some of the clues.
One randomly selected correct answer will win a £100 Maths Gear goody bag. Three randomly selected runners up will win a Chalkdust t-shirt. The prizes have been provided by Maths Gear, a website that sells nerdy things worldwide, with free UK shipping. Find out more at mathsgear.co.uk
To enter, submit the sum of the across clues via this form by 7 January 2017. Only one entry per person will be accepted. Winners will be notified by email and announced on our blog by 21 January 2017.

Continue reading →

Prize crossnumber, Issue 03

by Chalkdust. Published on 13 March 2016.

Our original prize crossnumber is featured on pages 44 and 45 of Issue 03.

Download Crossnumber #3 as a PDF, or read on!
~~Submit your answer~~ This competition has now ended.

Clarification: In 39D, the integers should be positive and distinct.
Clarification: The answer to 40A is not 5362, as some websites claim. 5362 is the number of positions that could face you after 3 moves, not the number of ways to play 3 moves.

Rules

Although many of the clues have multiple answers, there is only one solution to the completed crossnumber. As usual, no numbers begin with 0. Use of Python, OEIS, Wikipedia, etc. is advised for some of the clues.
One randomly selected correct answer will win a £100 Maths Gear goody bag. Three randomly selected runners up will win a Chalkdust t-shirt. The prizes have been provided by Maths Gear, a website that sells nerdy things worldwide, with free UK shiping. Find out more at mathsgear.co.uk
To enter, submit the sum of the across clues via this form by 22 July 2016. Only one entry per person will be accepted. Winners will be notified by email and announced on our blog by 30 July 2016.

Continue reading →

£100 Prize Crossnumber, Issue 02

by Chalkdust. Published on 6 October 2015.

Our original £100 prize crossnumber is featured on pages 44 and 45 of Issue 02.

Download Crossnumber #2 as a PDF, or read on!
~~Submit your answer~~ This competition has now ended.

Correction: There is an error in clue 4D. The 13th digit is actually larger than the 14th.
Clarification: In 40A ‘divisible’ should read ‘properly divisible’. The answer is not 2.
Clarification: In 9A ‘proper factors’ should be taken to mean factors not equal to the number. 1 should be included.

Rules

Although many of the clues have multiple answers, there is only one solution to the completed crossnumber. As usual, no numbers begin with 0. Use of Python, OEIS, Wikipedia, etc. is advised for some of the clues.
One randomly selected correct answer will win £100. Three randomly selected runners up will win a Chalkdust t-shirt. The prizes have been provided by G-Research, researchers of financial markets and investment ideas. Find out more at gresearch.co.uk.
~~To enter, submit the sum of the across clues via this form by 5 December 2015. Only one entry per person will be accepted.~~ This competition has now ended. Winners will be notified by email and announced on our blog by 19 December 2015.

Continue reading →

£100 Prize Crossnumber, Issue 01

by Chalkdust. Published on 24 March 2015.

Our original £100 prize crossnumber is featured on pages 34 and 35 of Issue 01.

Download Crossnumber #1 as a PDF, or read on!

Rules

Although many of the clues have multiple answers, there is only one solution to the completed crossnumber. As usual, no numbers begin with 0.
One randomly selected correct answer will win £100. Three randomly selected runners up will win a Chalkdust pen. The prizes have been provided by G-Research, researchers
of financial markets and investment ideas. Find out more at gresearch.co.uk.
To enter, email crossnumber@chalkdustmagazine.com with the sum of the across clues by 22 July 2015. Only one entry per person will be accepted. Winners will be notified by email by 1 August 2015.
Entry is now closed.

Continue reading →