Direct-touch devices such as electronic whiteboards provide an intuitive and interactive type of interface and are effective tools for education. However, they have some problems related to unnecessary changes in audience members' line of sight and obscuring of teaching materials by the operator. Therefore, we developed an electronic whiteboard system that combines multi-touch gesture operations with a special pie menu (a circular context menu). This pie menu differs from existing controls in that it can be hidden from the line of sight of audience members by the palm of the operator's hand. We have demonstrated that this proposed system enables an operator to control unnecessary movement in audience members' line of sight while still providing operational support.