set epsilon, a floating-point constant, to some very small number like 0.0001
get num, the number to determine its square root
set a floating-point variable called root to 1.0, this is the initial guess
set diff to the difference between root * root and num
set a floating-point variable called level to 1
while absolute value of diff is greater than epsilon
     while root * root < num

        increment root by level

/*   square root now somewhere between root and (root-1)
*/
     set root to root - level
     divide level by 10
     increment root by level
     set diff to the difference between root * root and num