By Ann Montague-Smith
By Santaniello, Joe
By Mark Patmore, Patmore, Mark
By Edwards, Roy, Mary, Ward, Alan
By Griffiths, Rose
By School Mathematics Project
By Abbey, Sally, Pointer, Lynne, Easterbrook, Trevor
By McDaniel, Yvette
By Carol Vorderman, Vorderman, Carol
By CGP Books, CGP Books
By Neill, Hugh, Quadling, Douglas
By Scottish Primary Mathematics Group, Matthews, Bethan, etc.
By Hopkins, Liz
By Fisher, Robert, Vince, Alan
By Owen, Annie
By SPMG, Scottish Primary Maths Group
By Prim-ed Publishing