YP Letters: Mental arithmetic and Morrisons offers that don't add up

A clearer grasp of numeracy would help shoppers determine whether supermarkets like Morrisons offer value for money.

JULIA Drake wrote about her grandad working as a grocer at the Co-op in Drighlington from the late 1920s (The Yorkshire Post, May 26).

She told how he handled, weighed and packed the various products and must have been a marvel at mental arithmetic... 6oz of ham at 3/4d a pound?

His mental arithmetic  was probably based on his knowledge of his times tables, which was nothing special in those times.

In old pre-decimal money, 3s/4d was 40d a pound (16 ounces) so it cost 21/2d (tuppence halfpenny) per ounce.

Therefore 6oz of ham  was 15d in old pennies  which was 1s/3d (or one and threepence) – no need for  pencil and paper – “and nine pence change from your two shillings madam”.

My own reliable mental arithmetic caused me to  almost scowl at an “offer” in Morrisons this week on packs  of six salad tomatoes. They  were priced at 68p with a  large ticket saying “buy three  for £2”.

To me that is an almost insulting offer of just 1.3p per pack, or 0.2p per tomato.

Do the top management at Morrisons study the figures before authorizing these phantom offers?