Lateral Thinking

(Apologies, this has been grabbed from another location - credit given in a while when I post the answer)

Add the pence - two pounds, 25p, £1.47, 16p, fifty pence.
(Clue, it's not 438)

Answers in the comments please


Answer:
The official answer is 506 from ITV, and here's how to fudge it (credit BBC Magazine Monitor that also show some other answsers and explanations)

first add everything. 200 + 25 + 147 + 16 + 50 = 438.

Now add the other sums which are visible. 5p (from the 25p) + 47p (from £1.47) + 7p (again from £1.47 [very tenuous!]) + 6p = 65p

Therefore 438 + 65 = 503.

Now add the 'p' from 25p and 16p and also the 'pence' from 50 pence giving an extra 3p.

Therefore 503 + 3 = 506p.

Although I like the approximation argument at the end of MM using 2lb of (new) pennies.