Thanks! It was mainly trial and error. At first I tried to find a slice that would fit in the length of entries I chose. I'm sure there is one, pi just goes on and on. But when none came up easily, I decided the slice didn't need to be precise, that was the beauty of pi. Then it was trial and error, trying to get a stack that would work with the constraints. And even now the end of the 11 letter entries doesn't have great fill. But although pi 'goes further obstinately', the time I had for constucting the puzzle was limited, so I decided it was good enough. Glad you enjoyed!