By R. Davison, L. Cochrane
By Scottish Primary Maths Group SPMG
By Sue Graves
By Orr-Love, Michael
By Wyn Brice, Tony Timbrell, Linda Mason
By Reiss, Michael J.
By Diana Coben, Elizabeth Atere-Roberts
By June Haighton, Debbie Holder, Veronica Thomas
By Ed Southall
By Iddo Gal
By CGP Books
By School Mathematics Project
By Richard Guy Meadows
By John Southcliffe Martineau
By David Blackie
By Collins GCSE
By Jamie Buchan
By Constance Reid
By Earl David Rainville
By Peter V. O'Neil
By Bulent Atalay
By Sarah Lindsay
By D. W. Ballentyne
By H M. Edwards
By H.M. Schey
By Rachel Thomas, Marianne Freiberger
By Pearce, Chris