Try out other rational types

[matbesancon]

There are other packages for handling exact / rational arithmetic that we can try out / show off in examples.
Alternatively, using high (fixed) precision integers could improve performance by a lot

https://github.com/rfourquet/BitIntegers.jl
jump-dev/MutableArithmetics.jl#33
https://github.com/JeffreySarnoff/FastRationals.jl

[pokutta]

i thinkt that would be a cool example. sometimes fix bit precision is enough also.