I see Marks & Spencer “stretched” Black Friday weekend over five days from 26 to 30 November. Is this something to do with the elasticity of demand (Black Friday shoppers play it safe, November 28)?
Peter Jones
The Business School, University of Gloucestershire
• Re early flowering forsythia (Letters, 28 November): we are equally bemused that our first snowdrops are about to open, two months earlier than normal.
Pete Dorey and Jane King
Bath, Somerset
• Surely having maths teachers from Shanghai is a mistake (Chinese maths class, 27 November)? Aren’t the Chinese renowned for their dim sums?
Pete Bibby
Sheffield