A numero-logical challenge
5 April 2008 - four new puzzles!

Fifteen Up is a Sudoku-style number logic puzzle. Unlike Sudoku, you will need to do some arithmetic. But don't worry; as the name suggests, you won't have to count beyond fifteen.
The rules of Fifteen Up are simple. The challenge is to divide the grid into 15 regions, with the numbers in each region totalling 15.
The regions can be any shape, so long as the sum of the numbers in each region is 15. All the numbers are used; there won't be any gaps or disjoint regions in the completed puzzle.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Click here for a carbon-conscious printable version of the puzzles above. You'll get all four puzzles on a single page, so you'll be using 75% fewer trees than before.

For the solutions to puzzles 9 to 12, click here.

 

 

 

 

 

 

 

 

Fifteen Up has replaced an earlier puzzle of mine, called simply Fifteen. This version required all the regions to be squares and rectangles, and was probably a bit too easy! You can still see the old Fifteen puzzles here.