The History of Kakuro Puzzles
From a 1950s American math magazine to Japanese puzzle books to worldwide apps. The full story of Kakuro.
Kakuro has a longer history than most people realize. It predates Sudoku by more than a decade. The puzzle traveled from America to Japan and back again before going worldwide in the 2000s. Here is the full story.
1950s-1960s: Cross Sums is born in America
The earliest known version of Kakuro appeared in 1950 in a puzzle magazine published by Dell in New York. It was called “Cross Sums.” The concept was simple: a crossword grid with numbers instead of words, where the intersecting runs had to add up to specific sums. It was popular among math puzzle fans but never reached mainstream audiences in the US.
1980s: Nikoli makes it Japanese
In 1980, the Japanese puzzle company Nikoli discovered Cross Sums and introduced it to the Japanese market. They renamed it “Kasan Kurosu” (addition cross), later shortened to “Kakuro.” Nikoli refined the puzzle format, standardized the rules, and began publishing it regularly. By the late 1980s, Kakuro was a staple of Japanese puzzle magazines, second only to Sudoku in popularity.
2005: The worldwide breakout
In 2005, The Guardian newspaper in London began publishing Kakuro puzzles alongside its daily Sudoku. The timing was perfect. Sudoku had just exploded worldwide, and people were hungry for something new. Kakuro gave them a puzzle that felt familiar but added a layer of arithmetic. Within months, other newspapers and puzzle publishers followed. The New York Times, The Times of London, and dozens of online sites added Kakuro to their offerings.
2010s: The app era
When smartphones became common, Kakuro moved to screens. Early apps were basic, but they made the puzzle accessible to millions of people who had never picked up a puzzle magazine. App stores now have dozens of Kakuro options. The best ones added features like pencil marks, hints, daily challenges, and difficulty ratings that paper puzzles cannot offer.
Today
Kakuro is still growing. Amazon sells thousands of Kakuro puzzle books each year. Apps like KakuroZen bring the puzzle to a new generation. Schools use it as a math enrichment tool. Senior centers use it for cognitive health programs. The puzzle that started in a 1950s American magazine is now a worldwide staple.
Why it endures
Kakuro has lasted because it hits a sweet spot: simple rules, infinite variety, and a perfect balance of math and logic. You can learn it in five minutes and spend a lifetime getting better at it. Few puzzles offer that kind of depth from such simple ingredients.