I can't see any reason you couldn't draw in chalk in a sketch pad, but it would be messy.

[ Well, the term is "starving artist" for a reason... ]

All right. I will do my best to keep both the materials and the cost reasonable. [ Give him maybe... five? Five minutes. And he'll be back with a selection of pencils and pads to be looked over and even tested if Koutarou so wishes. ]

These are some that I can personally recommend, or have come recommended to me.