to keep your brain active....

Three students spend £30 (£10 each) on pizza. When the pizza boy returns to the restaurant, his boss points out they should only have paid £25 between them. He takes £5 back, but helps himself to £2 and gives the students back £1 each. The students have now paid £9 each making a total of £27. If the boy has kept £2, where did the extra pound go because £27 + £2 = £29

You're adding £2 to the £27... when it should be added to £25.

They paid £25 and the pizza boy took £2 and they each have £1 in their pockets.

£25 + £2 + £3 = £30

The £1 hasn't gone anywhere, just a misdirection of words.

Lol, only me! As a child, my dad (the accountant turned accountancy lecturer, mmm!) used to make up these little quizzes to try to help me understand maths. He soon realised it was a total waste of time when I was unable to work out how many penny chews a little girl could buy with 10p and still have 5p change! Darling Daughter was clearly not going to fall into his footsteps, lol!

Will have to conclude with NumNums?!