An old favorite asks us to express the integers using only four 4's.
For example: 1 = 44/44; 2 = 4/4 + 4/4.
Irrationally perhaps, it has been suggested that we use pi instead.
We are allowed the operations of addition, subtraction, multiplication, division, square root and floor.
Floor, indicated by brackets, is simply the largest whole number: 3 = [pi].
Can you express the numbers 1-20 using 4 or fewer pi's?
Using spoilers, of course.
Enjoy.