that is, 1 and egin{matrix} frac{2}{3} end{matrix}; this is equivalent to taking 4 sqrt{egin{matrix} frac{2}{3} end{matrix}} or 3.26... as the value of π. But, Wallis argued, we have in fact a series 1, egin{matrix} frac{1}{6} end{matrix}, egin{matrix} frac{1}{30} end{matrix}, egin{matrix} frac{1}{140} end{matrix},... and therefore the term interpolated between 1 and egin{matrix} frac{1}{6} end{matrix} ought to be chosen so as to obey the law of this series[clarification needed]. This, by an elaborate method that is not described here in detail, leads to a value for the interpolated term which is equivalent to taking