Can you help me with these 5th grade math pattern problems?

[Chris in VA]

This is dd's homework, but she's not going to write down these answers; they are just for me! lol

 

So, here's the 1st pattern, which needs 3 more answers at the end:

 

1,1,2,4,3,9,_,_,_

 

I can't figure out how to get the 3, and what the p....

 

 

OH! I think I have it! Is the "rule" Counting numbers, counting number squared? So the answers would be 4,16,5?

 

Here's another--

2,9,3,14,_,_,_

 

I don't really understand how to approach these systematically. Is there an algebraic way or something?

[Pamela H in Texas]

You got the first one.

 

The second one, I'm thinking (again, using the counting numbers thing):

 

2, 9, 3, 14, 4, 21, 5

 

However, without the counting numbers, it could be:

 

2, 9, 3, 14, 26, 43, 83

 

LOL...want another possibility? end it with 4, 19, 5.

 

I could defend any of the three. If there were a couple more numbers, you'd know for sure which direction you needed to go. Since there isn't, I would think any defendable answer would be appropriate.

Edited September 30, 2010 by 2J5M9K

[Chris in VA]

You got the first one.

 

The second one, I'm thinking (again, using the counting numbers thing):

 

2, 9, 3, 14, 4, 21, 5

 

However, without the counting numbers, it could be:

 

2, 9, 3, 14, 26, 43, 83

 

LOL...want another possibility? end it with 4, 19, 5.

 

I could defend any of the three. If there were a couple more numbers, you'd know for sure which direction you needed to go. Since there isn't, I would think any defendable answer would be appropriate.

 

How do you get the 9,14 and 21?

[NanceXToo]

Apparently, I am NOT smarter than a 5th grader.

 

Math, ugh.

 

I'm lucky I know how many apples I have if I have three apples. I'd never be able to figure out those patterns!!

[hsmom3tn]

How do you get the 9,14 and 21?

 

previous number squared, then add 5

[Chris in VA]

Yes! Thanks so much.

 

Now, can anyone tell me how to get patterns in a more systematic way? I can ask at the high school board, too, if you think that will help.

[Pamela H in Texas]

for patterns, you really have to find it, then use the formula for future ones.

 

So for the one, you'd have x²+5. To be honest, I didn't do it that way though. I added the three numbers prior (14=2+9+3) as I was thinking "beginning 5th grade." I may have seen the other if I was thinking "middle school."

 

ETA: Here is a link: http://www.purplemath.com/modules/nextnumb.htm The part I like most is when he says:

"the right answer" is nothing more than whatever answer the author had in mind when he designed the exercise; you might "see" a completely different pattern that he hadn't intended. But as long as your answer is something that you can mathematically (or at least logically) justify, your answer should be acceptable, even if it isn't "right".

Edited September 30, 2010 by 2J5M9K