Make it a Group Effort
Never put a child on the spot in an embarrassing situation. It is agonizing for a child to be asked to come to the board and try to solve a problem they don't know how to do. To avoid this, have several children workout the problem on the board while other students work at their seats.This will enable you to monitor and evaluate students' work and progress, without singling out particular students. Additionally, the group effort will allow both students at the board and at their seats to see how to work out, correct and evaluate the problem.