Numberskull

Numberskull is an original puzzle from TopAccolades, designed by David Wolstenholme.

Place the 9 numbers in the bottom-right corner onto the empty white squares, and any of the four arithmetic operators onto the empty grey squares to complete 6 equations - 3 left-to-right and 3 top-to-bottom.

There is always a unique solution. The answer can be found methodically, with no guessing required, using arithmetic and, if appropriate, logic, to determine the positions of the numbers.

Has Check and Solve features.

Full Help facility, including explanation of notation for solution.

Always opens in Portrait orientation. The puzzle state is saved on exit so that you can continue from where you left off when you open it again.

The app is also available from i.compactfun.com if you cannot download from the Play Store. A web-based version that can be played on most browsers is also there.