mscroggs.co.uk
mscroggs.co.uk

subscribe

Puzzles

Backwards fours

If A, B, C, D and E are all unique digits, what values would work with the following equation?
$$ABCCDE\times 4 = EDCCBA$$

Show answer

If you enjoyed this puzzle, check out Sunday Afternoon Maths LXIV,
puzzles about digits, or a random puzzle.

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

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

Archive

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