Not 4-star difficulty. Completely logical. The "9" on the top row is different to the others! As a mathematician myself, I have never really understood the fascination with pi... why doesn't "e" have the same cult following?! Poor thing... Still, a nice puzzle!
The "9" on the top row is different to the others!
As a mathematician myself, I have never really understood the fascination with pi... why doesn't "e" have the same cult following?! Poor thing... Still, a nice puzzle!