Help Primary School Maths Question.

[Trem]

My son is 10 and he has 1 maths question for homework tonight, he has been told it is hard. His mum can't get the answer and there's no use me trying.

Any idea on the answer to the attached please chums and could you give pointers on how you get the solution?

Much thanks in advance.

 

[caLLous]

Dammit I can get 2011. This is for a 10 year old? Are the teachers at his school on crack?

The sum of the powers isn't going to be more than 10, I reckon. Because 5^5 is 3125, so the largest power can't be >4.

Ok, the answer is

Spoiler

4 + 0 + 2 + 3 = 9

. As for methodology, "fucking around in Excel" should cover it.

 

[Trem]

He's in the top group of maths, he's smart. His mum couldn't get it either Cal and she's a right maths nerd.

You think they've made it impossible to do on purpose?

Edit - The wife says she can get 1999 or 2010.

 

[caLLous]

He must be smart! Get him out of Stoke ASAP.

There's bound to be a way of working it out logically but i just pissed about in Excel until the numbers worked.

base   power
   5       4     625
   6       0       1
   7       2      49
  11       3    1331
                2006

So maybe you can take the results and work backwards to a method. :\

The closest I got was 1999 and 2011 before I realised we could use 0.

 

[Zarjazz]

There's bound to be a way of working it out logically but i just pissed about in Excel until the numbers worked.

As you said earlier you can get a max power each value can have which gives 400 possible combinations (5 * 5 * 4 * 4) but you're basically trying to solve a simultaneous equation with 4 unknowns. Unless there's some trick here I'm missing that's impossible without guessing.

 

[Trem]

He must be smart! Get him out of Stoke ASAP.

There's bound to be a way of working it out logically but i just pissed about in Excel until the numbers worked.

base   power
   5       4     625
   6       0       1
   7       2      49
  11       3    1331
                2006

So maybe you can take the results and work backwards to a method. :\

The closest I got was 1999 and 2011 before I realised we could use 0.

Cheers baby. Apparently the 0 is 1 as well has made some sense to the wife but still no solution yet.

It does seem a bit OTT for a 10 year old doesn't it?

 

[Jupitus]

It does seem a bit OTT for a 10 year old doesn't it?

Totally !

 

[old.Tohtori]

If they lower his grade or some such due to it, then yeah, completely OTT. If it's just a test of limits thing then it's cool.

 

[Lakih]

5J+6K+7L+11M=2006
2006-5-6-7-11=1977
The value of J+K+L+M=1977
Done.

 

[caLLous]

Huh. Ok. I asked someone cleverer than me who said to make a table of all the possible powers against the base numbers (powers of 0-4 except for the bigger 2 numbers which are 0-3), like this:

      0    1    2    3    4
 5    1    5   25  125  625
 6    1    6   36  216 1296
 7    1    7   49  343
11    1   11  121 1331

(base numbers down the left, powers across the top)

Then take just the last digit of each result so you can work out how to get the last digit of the answer (6). So with just the last digits, the table looks like:

    0  1  2  3  4
 5  1  5  5  5  5
 6  1  6  6  6  6
 7  1  7  9  3
11  1  1  1  1

Sooooo then you can see that you can knock 1 off of the 6 of 2006 for the 11 row because that's the only option. So we're looking for 5 (or 15) from the remaining 3 rows. The only 3 possible combinations of the first 2 rows are 6 (5+1), 7 (1+6) and 11 (5+6) so we know that we can only take the number that ends in 9 from the "7" row (none of the other numbers added to 6, 7 or 11 make 15). So we know that the power integer from the 7 row is 7^2. So none of the others can be 2 because all of the powers have to be different.

Ok, now we know that, because we added 9 to 6, the number from the first row must end in 5 and the number from the second row must end in 1. That makes it easier because there's only 1 1 in the second row, which is 6^0 (so none of the others can be 0). So after all of that, we're left with the following possibilities:

      0    1    2    3    4
 5         5       125  625
 6    1
 7             49
11        11      1331

From here it's pretty straightforward - take 1 and 49 from 2006 and then work out which remaining numbers from the 5 row and the 11 row add up to 1956, which can only be 625 (5^4) and 1331 (11^3):

      0    1    2    3    4
 5                      625
 6    1
 7             49
11                1331

Now, how a 10 year old is supposed to wrap his head around all of that, I have no idea.

 

[Trem]

Wow! Thanks cal.

I have just spoke to my boy about which teacher gave him this homework, waited until he left the room then suggested to Samm that our son's teacher is a fucking nimrod.

I would of just drawn a big knob on it and told him to fuck off (thankfully my son isn't like me but I fear my daughter is.....fun times ahead).

 

[Raven]

If he is doing that at 10, imagine what sort of witchcraft they will be getting him to do at 15/16!

 

[Gwadien]

I'm waiting for @DaGaffer to have an input.

BACK IN MY DAY WE WERE DOING THIS WHILST DOWN T PIT

 

[Jupitus]

If he is doing that at 10, imagine what sort of witchcraft they will be getting him to do at 15/16!

At least we will soon know which way the toilet paper should be hung, or the answer to the conveyor belt plane, or if global warming really IS a thing

 

[Jupitus]

... and Trem has someone in the house who can put shelves up too

 

[caLLous]

Christ, they might even be level. What a time to be alive.

 

[Trem]

... and Trem has someone in the house who can put shelves up too

Hey fuck off I'm the shelf lord in this house!

That conveyor belt plane thing I stayed right the way out of, I couldn't get my head around it.

My children are both so smart, so is my wife but none of them have common sense which means I get to have lots of fun.

Edit - just check out his spazzy writing in the original post though.

 

[Scouse]

our son's teacher is a fucking nimrod.

Or he's a good teacher that's challenging his bright pupils the way he should tbh

 

[Zarjazz]

Huh. Ok. I asked someone cleverer than me who said to make a table of all the possible powers against the base numbers ... <snipped out some clever shit>

Fuck that, I'd just knock up some code in a few minutes to try every combination instead

 

[leggy]

Conveyor belt plane

It wouldn't take off!!!

It has nothing to do with the rotational speed of the wheels!!!!

 

[Trem]

Or he's a good teacher that's challenging his bright pupils the way he should tbh

No. Nimrod. Challenge them thats good, give something that Hawking would struggle with is just shit.

I'm going to go and arm wrestle this teacher fuck tomorrow

 

[Scouse]

No. Nimrod. Challenge them thats good, give something that Hawking would struggle with is just shit.

Rubbish. It's not that bad.

School should be very hard for the brightest pupils - if, as you say your son's one. It's all too often aimed at the middling pupils - so the thickies struggle and underachieve and the clever ones become bored and underachieve.

You *must* be challenged if you're to get better. And part of being challenged is being, regularly, set stuff you may not be able to do.

 

[Gwadien]

Rubbish. It's not that bad.

School should be very hard for the brightest pupils - if, as you say your son's one. It's all too often aimed at the middling pupils - so the thickies struggle and underachieve and the clever ones become bored and underachieve.

You *must* be challenged if you're to get better. And part of being challenged is being, regularly, set stuff you may not be able to do.

Depends really.

Some kids get REALLY stressed about their homework (Especially the brighter ones.)

Unless you make it absolutely clear that what they're attempting is ridiculously hard it could backfire massively and cause a downward spiral.

 

[Scouse]

My son is 10 and he has 1 maths question for homework tonight, he has been told it is hard.

@Gwadien - Life is hard. Deal.

Failure is an integral part of learning. Well, worthwhile learning anyway...

 

[Gwadien]

Ah okay, fair dues.

 

[Bodhi]

Don't worry about getting the right answer, the teacher will be just like, ah it doesn't matter, they're just numbers far away!

Or something.

 

[Syri]

It wouldn't take off!!!

It has nothing to do with the rotational speed of the wheels!!!!

ah, but what if you add some fucking huge fans for airflow? I think we're getting somewhere here...

 

[Zarjazz]

Make him hand this in so he can tell his crazy teacher he's passed CS early too.

#!/usr/bin/python
# series.py - calc stuff

"""Caclulate Power Series."""

import os, io, math

target = 2006
numbers = [5, 6, 7, 11]

def calc(s, p, t):
   f = 0
   for i in range(len(s)): f += math.pow(s[i], p[i])
   if f == t: return True
   return False

if __name__ == '__main__':
   cutoff = [int(math.log(target, i)) for i in numbers]
   l = len(numbers);
   powers = [0 for i in range(l)]

   while True:
     if calc(numbers, powers, target):
       print "numbers:", numbers, "powers:", powers, "=", target
     if powers == cutoff: break;

     n = 0
     while True:
       powers[n] += 1
       if powers[n] > cutoff[n]:
         n += 1; i = 0
         while i < n: powers[i] = 0; i += 1
         if (n < l): continue
       break

Output:

numbers: [5, 6, 7, 11] powers: [4, 0, 2, 3] = 2006

 

[TdC]

brute force much Zarjazz?

I like "hard" puzzles but I am shit at them tbh. With my odd schooling (int'l US based)I knew a lot of stuff about DNA at age 7, but I don't think anyone ever uttered the words "non-negative integer" to me till I was at least 22.

 

[Moriath]

Rubbish. It's not that bad.

School should be very hard for the brightest pupils - if, as you say your son's one. It's all too often aimed at the middling pupils - so the thickies struggle and underachieve and the clever ones become bored and underachieve.

You *must* be challenged if you're to get better. And part of being challenged is being, regularly, set stuff you may not be able to do.

You cant have education for the masses that excludes a proportion. What you need is streamed schools. That push each group to their max. This does not exist. So you get middling so some ar epushed and some are bored. Been there done that. Still being bored in life