mscroggs.co.uk
mscroggs.co.uk

subscribe

Puzzles

7 December

There is a row of 1000 closed lockers numbered from 1 to 1000 (inclusive). Near the lockers, there is a bucket containing the numbers 1 to 1000 (inclusive) written on scraps of paper.
1000 people then each do the following:
Today's number is the number of lockers that will be closed at the end of this process.

Show answer

6 December

This puzzle was part of the 2018 Advent calendar.
This puzzle is inspired by a puzzle that Daniel Griller showed me.
Write down the numbers from 12 to 22 (including 12 and 22). Under each number, write down its largest odd factor*.
Today's number is the sum of all these odd factors.
* If a number is odd, then its largest odd factor is the number itself.

Show answer

5 December

I make a book by taking 111 sheets of paper, folding them all in half, then stapling them all together through the fold. I then number the pages from 1 to 444.
Today's number is the sum of the two page numbers on the centre spread of my book.
Tags: numbers, books

4 December

Today's number is the number of 0s that 611! (611×610×...×2×1) ends in.

Show answer

3 December

Put the digits 1 to 9 (using each digit exactly once) in the boxes so that the sums are correct. The sums should be read left to right and top to bottom ignoring the usual order of operations. For example, 4+3×2 is 14, not 10. Today's number is the product of the numbers in the red boxes.
++= 11
- + ×
+-= 11
- - -
++= 11
=
-11
=
11
=
11

Show answer

Tags: numbers, grids

2 December

Today's number is the area of the largest dodecagon that it's possible to fit inside a circle with area \(\displaystyle\frac{172\pi}3\).

Show answer

1 December

There are 5 ways to write 4 as the sum of 1s and 2s:
Today's number is the number of ways you can write 12 as the sum of 1s and 2s.

Show answer

Tags: numbers

Cryptic crossnumber #2

In this puzzle, the clues are written like clues from a cryptic crossword, but the answers are all numbers. You can download a printable pdf of this puzzle here.
12
3
4
5

Show answer

Archive

Show me a random puzzle
 Most recent collections 

Advent calendar 2023

Advent calendar 2022

Advent calendar 2021

Advent calendar 2020


List of all puzzles

Tags

dodecagons geometry multiples hexagons shape integration ave proportion planes multiplication determinants coordinates quadratics complex numbers digits spheres pentagons dice expansions cryptic clues colouring indices mean crosswords circles unit fractions angles square numbers calculus 3d shapes routes cards prime numbers addition graphs combinatorics triangle numbers floors cubics folding tube maps geometric means median elections polygons algebra 2d shapes products gerrymandering integers people maths matrices grids polynomials rectangles pascal's triangle means books menace rugby games square roots doubling coins time shapes factors crossnumber chocolate ellipses numbers money percentages digital products scales differentiation chess wordplay star numbers partitions perfect numbers surds sum to infinity cryptic crossnumbers irreducible numbers regular shapes christmas dominos bases consecutive numbers albgebra geometric mean the only crossnumber speed palindromes sets chalkdust crossnumber even numbers sport arrows triangles odd numbers parabolas symmetry taxicab geometry squares crossnumbers tangents range cube numbers dates quadrilaterals sums tournaments decahedra lines division sequences number volume fractions logic probability averages probabilty binary consecutive integers digital clocks advent functions remainders area factorials axes balancing clocks perimeter tiling trigonometry

Archive

Show me a random puzzle
▼ show ▼
© Matthew Scroggs 2012–2024