With the standard cardinal numbers, a d-pi won't work. But I can figure something out to within a certain degree of precision.
D-Pi? I can do it. Take a big plastic six sider, label each side once from the following set {Pi, 5Pi/6, 4Pi/6, 3Pi/6, 4Pi/6, 2Pi/6, Pi/6} There you go, 1dPi. :p