mscroggs.co.uk
mscroggs.co.uk

subscribe

Puzzles

15 December

There are 5 ways to make 30 by multiplying positive integers (including the trivial way):
Today's number is the number of ways of making 30030 by multiplying.

Show answer

14 December

During one day, a digital clock shows times from 00:00 to 23:59. How many times during the day do the four digits shown on the clock add up to 14?

Show answer

11 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 red digits.
+÷= 2
+ ÷ ÷
÷÷= 3
÷ - ÷
÷÷= 1
=
2
=
1
=
1

Show answer

Tags: grids, numbers

9 December

Arrange the digits 1-9 in a 3×3 square so that: all the digits in the first row are odd; all the digits in the second row are even; all the digits in the third row are multiples of 3; all the digits in the second column are (strictly) greater than 6; all the digits in the third column are non-prime. The number in the first column is today's number.
all odd
all even
all multiples of 3
today's numberall >6all non-prime

Show answer

Tags: numbers, grids

8 December

Carol uses the digits from 0 to 9 (inclusive) exactly once each to write five 2-digit even numbers, then finds their sum. What is the largest number she could have obtained?

Show answer

Tags: numbers

6 December

Noel's grandchildren were in born in November in consecutive years. Each year for Christmas, Noel gives each of his grandchildren their age in pounds.
Last year, Noel gave his grandchildren a total of £208. How much will he give them in total this year?

Show answer

4 December

There are 5 ways to tile a 3×2 rectangle with 2×2 squares and 2×1 dominos.
Today's number is the number of ways to tile a 9×2 rectangle with 2×2 squares and 2×1 dominos.

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 largest number you can make with the digits in the red boxes.
++= 21
+ × ×
++= 10
+ ÷ ×
++= 14
=
21
=
10
=
14

Show answer

Tags: numbers, grids

Archive

Show me a random puzzle
 Most recent collections 

Advent calendar 2019

Sunday Afternoon Maths LXVII

Coloured weights
Not Roman numerals

Advent calendar 2018

Sunday Afternoon Maths LXVI

Cryptic crossnumber #2

List of all puzzles

Tags

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

Archive

Show me a random puzzle
▼ show ▼
© Matthew Scroggs 2012–2020