The number of decimal places can be set by two methods in SMath 0.90. First is from the Menu Tools->Options->Calculations->Decimal Places and the second is by the right mouse button context menu. It may have been but I wasn't aware of the context menu in 0.89.

One draw back to this is if you set the precison by the context menu there is no way to revert back without touching each one. If you end up with a lot of results with override precision of 0 decimal places and all results get small you get a bunch of zero results. A good feature would be to selecta all and revert back to default precision.