The Times Killer Su Doku Book 9 : 150 Challenging Puzzles from the Times

The latest volume in the hugely popular Killer Su Doku series from the puzzles suppliers to the Times, featuring the highest-quality puzzles with an extra element of arithmetic. This ninth addition to the successful Times Killer Su Doku series will test your skills to the limit, adding the challenge of arithmetic and taking Su Doku to a new and even deadlier level of difficulty. The puzzles use the same 9x9 grid as Su Doku but with an added mathematical challenge. The aim is not only to comp