A board with flappers on top of each number. The numbers are checked by closing the flap.
                                                            
                                                     
                        
                                                
                        
                        
                            a re-usable plastic board that contains pre-printed numbers.
                                                            
                                                     
                        
                                                
                        
                        
                            A hand-held re-usable plastic board with pre-printed numbers, usually in a 4x4 format. Numbers are marked off when called with shutters.