mscroggs.co.uk
mscroggs.co.uk

subscribe

Advent calendar 2023

16 December

Some numbers can be written as the sum of two or more consecutive positive integers, for example:
$$7=3+4$$ $$18=5+6+7$$
Some numbers (for example 4) cannot be written as the sum of two or more consecutive positive integers. What is the smallest three-digit number that cannot be written as the sum of two or more consecutive positive integers?

Show answer & extension

Archive

Show me a random puzzle
 Most recent collections 

Advent calendar 2025

Advent calendar 2024

Advent calendar 2023

Advent calendar 2022


List of all puzzles

Tags

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

Archive

Show me a random puzzle
▼ show ▼
© Matthew Scroggs 2012–2026