A schoolboy who perfectly memorised his multiplication tables still managed to get one less than top marks - because the 99p store poster he'd been using to learn was wrong.
Kelly Haynes was livid after her eight-year-old son came home from school "distraught" because he'd been marked down on his 12 times table.
Incensed Kelly, 25, from Islington, north London, bought learning aids from her local 99p Store which contained a schoolboy howler on the 12 times table.
The dud poster claimed 12 x 12 was 148, not the correct 144.
Supermarket worker Kelly said: "My eight-year-old is starting to do proper times tables in school so I thought I'd help him out with a treat.
"He had a test one Friday and came back really upset and said 'I got one wrong I put 148 for 12 x 12 and they said it was a mistake but it's not.'
"I said 'the answer is 144 honey' and he went 'no it's not, my poster says it's 148.'
"When we got home I saw he was right, and he was still so upset and demanded I take them down because he would have got 100 per cent in his test if there wasn't this huge mistake.
"I bought them from the 99p Store and I complained three weeks ago. I'm so annoyed though, it's embarrassing."
An apology email from 99p Stores said: "The supplier has been in contact saying they made all the amendments to the poster when redesigning them.
"They will be in contact soon and send a poster free of charge."