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 Various
By Mills, Steve, Koll, Hilary, Barber, Tina
By Patilla, Peter
By Pluckrose, Henry, Fairclough, Chris
By Neill, Hugh, Quadling, Douglas
By Bryant-Mole, Karen
By Ann Montague-Smith
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 Ladybird
By Rosemary Russell
By McDougall, Susan
By E. Albany, Anne Woodman, Albany, E., Woodman, Anne