Welcome to my 112th gems post. This is where I share some of the latest news, ideas and resources for maths teachers. 1. Classic ErrorsI like this activity suggested by James Tanton (@jamestanton). James asks ‘Would taking classic and tempting errors “head-on” be a worthwhile classroom activity and discussion?’.  It’s worth reading the responses in the thread. In it Cathy Yenca‏ (@mathycathy) recommends the classic resource ‘Algebra Atrocities’ which is worth a look.2. Geogebra PercentagesThanks to Mark Horley (@mhorley) for sharing some…