So, this was passed on to me by someone who knows I know math. I have no idea if she copied the problem correctly, but she says she did. Her son got this problem on a 3rd grade homework assignment:

"Use the rule to fill in the missing numbers.
W, 1, 2, 3, 5, 7, 10, 30, W
X, blank, blank, blank, blank, blank, blank, blank, W-1"

Anybody with ideas? I've got some possibilities, but the hard part is finding something that could remotely fit in a 3rd grade curriculum. Am I dense?

I'm thinking there has to be more to the problem that she either didn't copy down, or the teacher did not put on the sheet, or something. This is driving me nuts.

[Edited on April 30, 2009 at 8:58 AM. Reason : a]

4/30/2009 8:58:27 AM

so the first half has two Ws and the second half has an X and a W-1?

4/30/2009 9:00:52 AM

the answer is TWW

4/30/2009 9:01:32 AM

^^yep. So she says.

It is interesting, though probably irrelevant, that these are the same numbers as the maturities (in years) available on US T-Bills (1, 2, 3, 5, 7, 10 and 30 years).

[Edited on April 30, 2009 at 9:05 AM. Reason : s]

4/30/2009 9:03:31 AM

sounds like someone copied it wrong

4/30/2009 9:04:51 AM

Yeah, the W-1 has to be wrong.

x,2,3,6,8,11,31,x would make sense. especially on a 3rd grade level.

4/30/2009 9:06:58 AM

That's what I told her. But even if you take out the w's and x's and just try to figure out the pattern in that series, I'm still at a loss.

I've asked her twice to check that she copied it correctly. It's going to be a little insulting if I go back again and say, "Ummm, yeah, the problem is still wrong. Either you or the teacher fucked up."

Djeternal may be on the right track. Maybe you're just supposed to add or subtract one from the first series and keep it intact, and not actually find a pattern. That would be gay. But the 3rd grade is pretty gay.

[Edited on April 30, 2009 at 9:09 AM. Reason : a]

4/30/2009 9:07:00 AM

http://rr-bb.com/showthread.php?p=1212365

4/30/2009 9:12:01 AM

YOU TAKE THAT BACK

4/30/2009 9:12:13 AM

^^lol, and that person's daughter may be in the same class as my friend's son.

4/30/2009 9:14:38 AM

One rule is +1,+1,+1,+1,+1,+1,+1,+1,-1

w -> x
1 -> 2
2 -> 3
3 -> 4
5 -> 7
7 -> 8
10 -> 11
30 -> 31
W -> W-1 or V

[Edited on April 30, 2009 at 9:16 AM. Reason : -]

4/30/2009 9:15:50 AM

I'm still trying to figure out how the rule can start with W and end with W. Doesn't make any sense to me.

4/30/2009 9:18:40 AM

its probably just subtracting 1 from all the numbers listed

w -> x
1 -> 0
2 -> 1
3 -> 2
5 -> 4
7 -> 6
10 -> 9
30 -> 29
W -> W-1

[Edited on April 30, 2009 at 9:19 AM. Reason : are the missing numbers the blanks and we're wasting time with the w's and x's?]

4/30/2009 9:19:14 AM

HA @ Rapture Ready

4/30/2009 9:20:48 AM

^^ x wouldn't be subtracting, it would be adding

[Edited on April 30, 2009 at 9:21 AM. Reason : a]

4/30/2009 9:21:01 AM

but at the end you get w -> w-1

lol, each end is going a different way

4/30/2009 9:22:02 AM

if W-1 = X

then the solution is X,0,1,2,4,6,9,29,X

W could represent any # whatsoever. so when W = 1, X = 0. when W = 2, X = 1 etc.

i dont think 3rd graders would be able to comprehend that yet though. but it was a long time ago when i was in 3rd. maybe kids are smarter nowadays. 'course, my answer could be completely wrong but thats the way my brain sees it.

4/30/2009 10:15:50 AM

^ that seems right to me

4/30/2009 10:41:27 AM

seems a bit advanced for 3rd grade math classes

4/30/2009 10:44:06 AM

is this Jesus' math?

This is Jesus' math, isn't it?

4/30/2009 10:44:16 AM

jesus doesn't need math, idiot

4/30/2009 10:45:15 AM

(W-1)*X^W = the plane takes off

4/30/2009 10:45:57 AM

sure, he doesn't "need" math

but he still loves solving a theorem every now and again

4/30/2009 10:46:07 AM

3rd grade. Wow. It's been a loooong time but all I remember from those days was screwing up multiplication tables left and right. Forget solving algebra-like problems with mistakes in the assumptions.

[Edited on April 30, 2009 at 11:16 AM. Reason : -ICwhatUdidThere]

4/30/2009 11:10:31 AM

i don't know if i'd call this "math", but alright.

4/30/2009 11:45:54 AM

Quote :

"One rule is +1,+1,+1,+1,+1,+1,+1,+1,-1 w -> x 1 -> 2 2 -> 3 3 -> 4 5 -> 7 7 -> 8 10 -> 11 30 -> 31 W -> W-1 or V"

would be my guess, but this is a weird problem....

4/30/2009 12:32:11 PM

^i dont really know how that came about. nothin suggests you should add one to everything.

there has to be a pattern and one part of it is the letter at the front and the letter at the end are the same so...W-1 = X

im not gonna get any work done until we figure this out.

4/30/2009 12:46:26 PM

z=26
y=25
x=24
w=23
v=22

going from w to x is +1

w-1 = v

[Edited on April 30, 2009 at 1:12 PM. Reason : but again, this is a really weird problem]

4/30/2009 1:11:57 PM

I think the next sequence is: X, 1, 3, 5, 7, 11, 21, 105, V

2, 3, 5, and 7 are all prime numbers. In the new sequence, they advance to their direct prime number successors.

10 = 2*5, 30 = 2*3*5, so columns 3 and 5 are multiplied to get column 7 and columns 3, 4, and 5 are multiplied to get column 8.

It's a new layer of weird!

4/30/2009 1:34:34 PM

^^then why is the first and last letter the same in the first one??

this is blowin my mind

4/30/2009 1:41:17 PM

There's no explanation for all this.

Except one.

The teacher fucked up royally. And that makes a lot of sense. People who know math simply do not get degrees in education. And even the few who do will not go into elementary education. The teacher is instructing her intellectual equals.

4/30/2009 1:50:24 PM

/win

4/30/2009 2:00:10 PM

^^accepted

4/30/2009 6:14:26 PM

Quote :

"z=26 y=25 x=24 w=23 v=22 going from w to x is +1 w-1 = v "

The only way this makes sense is if you look at X and W as purely being variables, not letters. They are not letters (uhh... sort of). They are there to indicate the transform.

This is more of a logic question, not a strict math question.

4/30/2009 7:06:51 PM

what is this i dont even

4/30/2009 7:27:42 PM

Quote :

"Use the rule to fill in the missing numbers."

The teacher probably wrote an equation or some shit on the board.

4/30/2009 7:36:30 PM