OK, I looked at the question, thought that 'maths is about finding the simplest and easiest answer' and said '120 x 1'. I'm kicking myself slightly for not thinking of sqrt(120) x sqrt(120) first :)

JA(7) saw that 120 is a multiple of 20 and worked out that '20 x 6' was 120.

L said '2 x 60'.

Adult visitor P said that seven year olds probably wouldn't know anything higher than their twelve times tables and said '12 x 10'.

You lot had...

10 x 12 - two people

6 x 20 - three people

3 x 40 - one person

2 x 60 - two people

1 x 120 - one person

Three people gave lots of answers, typically all the natural (1, 2, 3, ..) ones

One person said that 'number' doesn't mean 'integer', which is true, but you weren't asked to give every possible answer, just (at least) one possible one. The marking notes said that (for example) 240 x 1/2 was to be treated as correct, for example.

One person said 30 x 40, which alas is 1,200. Of course, those could have been the numbers Harry picked too - it doesn't say he got the sum right :)

I'm afraid I suspect Paul's attempt (two complex numbers) would get no marks, although this is partly my prejudice about the maths of infant school teachers: would they recognise the answer as being correct?

- An infinite number of correct answers, part two

ciphergothyouconfident that my answer is correct?didn't anyone else try for a "weird" answer?

lovingbothLet's see...

(10, −10)⋅(6, 6) = (10x6 - -10x6, -10x6 + 10x6)

= (60 - -60, -60 + 60)

= (60 + 60, 0)

= (120, 0)

aka 120, so yep.

I'll leave it to you to explain complex numbers to people :)

Nope, including the square root was as wierd as anyone else got. Mind you, I haven't had a response from some of the other maths people yet.

a_musing_amazonThough of course 120/(a+bi) is not expresed in standard complex form which would, I think, be 120a/(a^2+b^2) - 120b/(a^2+b^2)i.

(Deleted comment)lovingbothTeaching children that one times 'something' = 'something' now happens before any other multiplication from what I've seen.