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Talking with a friend today, he mentioned a puzzle that one of his friends has got. Heavily edited transcript follows, my friend's questions in [brackets]. What have you got, STW?
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My son was set a task for his homework and I'm convinced it's a trick question. He was asked to use numbers 1 through 9 inclusive to make 1500. I got as far as 387+495+621= 1503 before wanting to kill something.
[No more clarification, i.e. all the numbers must be used, must be used one and once only!]
yep - each number once
[Only addition ?]
no - any basic operation - addition, subtraction, multiplication, division
(NB this wasn't a task set to the whole class but just to the one child, the kid's seemingly ahead academically and the parent suspects that it's an attempt to 'shut him up,' which is a bit shit if true.)
Literally no googling, I got it first time
(9*8*7*6)/2-(5-4-3)/1
I managed to get to it, but not like that ^^^
((2+3)*(4*5)) * (6+8+9-(7+1))
My kids both pretty much this question but they had didn’t have to use every number just the right ones to get the result. Is your friend sure?
123 + 456 + 78 + 9 = 666
1234 – 567 + 8 – 9 = 666
9 + 87 + 6 + 543 + 21 = 666
just to wind the teacher up 😉
My first try:
(1+2+3+4)*5*(6+7+8+9)
Quite neat. More luck than judgement on that bit.
(9*8*7*6)/2-(5-4-3)/1
Ah, almost. You need (5+4+3), typo I assume.
Nice.
just to the one child, the kid’s seemingly ahead academically and the parent suspects that it’s an attempt to ‘shut him up,’ which is a bit shit if true.
Why is it shit? What else would you have the teacher do? Seems like an involved challenge to set a brighter kid, can't see a problem here. I'd have enjoyed that as a kid.
Liking everyone else answers more
I’m post nights so my brain is pretty much on shut down but I’m not getting 1500 with Boardin’s answer.
Ah now I’ve posted Cougar has replied.
Is your friend sure?
You know as much as me, I copied the text from a conversation CC:ed to me.
Why is it shit?
Because as I said, "the parent suspects that it’s an attempt to ‘shut him up,’ " But let's not go down this rabbit hole for once, hey.
9*8=72
72*7=504
504*3=1512
6-5=1
1*1=1
1+2=3
3*4=12
1512-12=1500
which equals
((9*8)7)3)-4((6-5)1)+2)
Ah, almost. You need (5+4+3), typo I assume.
Nice.
Ah yes we'll spotted, just messed up the brackets Was trying to say
9 x 8 x 7 x 6 = 3,024
Then
/ 2 = 1,512
Then
1,512 - 5 - 4 - 3 = 1,500
/1 = 1,500
BTW, for reference, the kid in question is 8.
I've suggested that the friend-of-a-friend reframes the question as "add symbols to (1234)5(6789) to equal 1500." That maybe should be more doable by an 8 year old maths protogé?
just messed up the brackets
Aha, yes.
I think its an interesting challenge for a kid good at arithmetic.
(1+9) X (2+8) = 100
7+6+4+3-5= 15
15 × 100 = 1500
Cheers Tonto that’s the way I was trying to go but my brain is deader than normal.
the parent suspects that it’s an attempt to ‘shut him up,’
Depends what he's been saying. If it's "Sir, I'm bored, this is all too easy" then again I'm not seeing a problem. After all, we are all enjoying having a crack at it aren't we? I'm guessing the teacher wasn't about to bollock him if he didn't get it right. I'd be flattered to be given an extra hard challenge at 8 tbh.
Just wondering what you would have preferred the teacher do?
Once more with feeling,
the parent suspects that it’s an attempt to ‘shut him up,’ which is a bit shit if true.
If it's an inventive challenge to give the smart kid something to get his teeth into then yes, that's really very cool. If it's an "impossible problem" they've pulled out of their arse in an attempt to knock down a precocious 8-year old a peg or two then it rather isn't.
You're usually a voice of reason on here Mols, please don't pick a fight where there's none to be had. It was a throwaway comment I made expressly to try and avoid someone derailing the thread with a mass debate about the validity of the parent's suspicion.