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

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

Archive

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