Inshi no heya

It is a specific form of the KenKen puzzle genre where every operation is implied to be multiplication.

Inshi no heya is played on a square grid, broken into "rooms" by heavier borders.

Each room may run either horizontally or vertically, and has a small number appearing in its upper left corner.

One technique relies on the fact that the product of every row and column is a fixed number.

Although the creator named the puzzle insū bunkai (factorization), the editor replaced it with inshi no heya, which sounds less technical.