# Thread: 5th Grade Math: Rods

1. ## 5th Grade Math: Rods

Hello everyone. One of my nephews got stuck on two questions involving rods in his 5th grade math class. He decided to text me his questions because he knows I love math. However, I do not understand this new COMMON CORE math nonsense. See picture for additional information.

The biggest square represents one hundred unit cubes.
The 4 vertical rods represent 10 unit cubes.
The 5 individual pieces represent 1 unit cube each.

Question:

If the base ten blocks shown are divided into 5 equal groups, what should be done first?

A) Exchange the 100 flat for 10 rods
B) Exchange the 100 flat for 100 unit cubes
C) Exchange 4 ten rods for 40 unit cubes
D) Exchange the 100 flat for 7 ten rods and 30 unit cubes

2. ## Re: 5th Grade Math: Rods

I would exchange the 100 flat for 6 10 rods so we have a total of 10 10 rods, and 40 unit cubes so we have a total of 45 unit cubes. 10 and 45 are both divisible by 5.

3. ## Re: 5th Grade Math: Rods Originally Posted by MarkFL I would exchange the 100 flat for 6 10 rods so we have a total of 10 10 rods, and 40 unit cubes so we have a total of 45 unit cubes. 10 and 45 are both divisible by 5.
Yes, I'd do that too. But I suppose, strictly speaking, the first step would be A) Exchange the 100 flat for 10 rods. Second step would be to exchange 4 ten rods for 40 unit cubes.

4. ## Re: 5th Grade Math: Rods Originally Posted by Debsta Yes, I'd do that too. But I suppose, strictly speaking, the first step would be A) Exchange the 100 flat for 10 rods. Second step would be to exchange 4 ten rods for 40 unit cubes.
I agree...I was hoping the OP could surmise that from what I posted. 5. ## Re: 5th Grade Math: Rods Originally Posted by MarkFL I agree...I was hoping the OP could surmise that from what I posted. Ooops … sorry!

6. ## Re: 5th Grade Math: Rods Originally Posted by Debsta Ooops  sorry!
50 lashes with a wet textbook!

-Dan

7. ## Re: 5th Grade Math: Rods Originally Posted by topsquark 50 lashes with a wet textbook!

-Dan
$\displaystyle {ouch}^50$

8. ## Re: 5th Grade Math: Rods Originally Posted by Debsta Ooops  sorry!
Oh, I didn't mean you shouldn't have posted. I was just explaining my reasoning for being somewhat vague. Sometimes I'm vague without meaning to be, as I skip erratically from site to site.

9. ## Re: 5th Grade Math: Rods Originally Posted by MarkFL I would exchange the 100 flat for 6 10 rods so we have a total of 10 10 rods, and 40 unit cubes so we have a total of 45 unit cubes. 10 and 45 are both divisible by 5. Originally Posted by Debsta Yes, I'd do that too. But I suppose, strictly speaking, the first step would be A) Exchange the 100 flat for 10 rods. Second step would be to exchange 4 ten rods for 40 unit cubes. Originally Posted by MarkFL I agree...I was hoping the OP could surmise that from what I posted.  Originally Posted by MarkFL Oh, I didn't mean you shouldn't have posted. I was just explaining my reasoning for being somewhat vague. Sometimes I'm vague without meaning to be, as I skip erratically from site to site.
Since I am not wanted at the MHB and Jason's site, look for my questions here.

10. ## Re: 5th Grade Math: Rods

This question is, in my opinion, to advanced for 5th graders. Totally ridiculous!! What ever happened to regular math operations like 5 × 5 or 100/25 or 45 - 4 or 99 + 99?

11. ## Re: 5th Grade Math: Rods Originally Posted by harpazo This question is, in my opinion, to advanced for 5th graders. Totally ridiculous!! What ever happened to regular math operations like 5 × 5 or 100/25 or 45 - 4 or 99 + 99?
What? You mean a set of binary realtions $\displaystyle \mathbb{R} \to \mathbb{R}$ ? If you dislike the problem then why did you post it??

-Dan

PS Probably the reason the other sites get annoyed with you is for posting so many problems. I understand you are trying to get better at doing word problems but you have posted a number of equivalent problems that you should, by now, be able to handle. In my humble opinion you are at the point where you need to find a source of confidence, not more Math problems.

12. ## Re: 5th Grade Math: Rods Originally Posted by topsquark What? You mean a set of binary realtions $\displaystyle \mathbb{R} \to \mathbb{R}$ ? If you dislike the problem then why did you post it??

-Dan

PS Probably the reason the other sites get annoyed with you is for posting so many problems. I understand you are trying to get better at doing word problems but you have posted a number of equivalent problems that you should, by now, be able to handle. In my humble opinion you are at the point where you need to find a source of confidence, not more Math problems.
My Christian point of view annoyed many tutors in other sites. It is really dumb for sites to have, for example, a Religion Forum, and then get upset when I express my understanding of Scripture in the correct forum. Makes no sense to me.

As far as math questions, my main concern is to "master" the ability to convert word problems to equations. I can solve high school level equations (algebra 1 and 2). My biggest problem is trying to understand what the written words say leading to the right equation set up. I have been struggling with this stuff for years, even back in my school days.

13. ## Re: 5th Grade Math: Rods Originally Posted by harpazo My Christian point of view annoyed many tutors in other sites. It is really dumb for sites to have, for example, a Religion Forum, and then get upset when I express my understanding of Scripture in the correct forum. Makes no sense to me.
I don't want to further bring drama from another site to this one, but if you wish to know the actual reason Jason banned you from his site, as least as I understood it, shoot me a PM.

14. ## Re: 5th Grade Math: Rods Originally Posted by MarkFL I don't want to further bring drama from another site to this one, but if you wish to know the actual reason Jason banned you from his site, as least as I understood it, shoot me a PM.
Check your PM.

15. ## Re: 5th Grade Math: Rods Originally Posted by harpazo My Christian point of view annoyed many tutors in other sites. It is really dumb for sites to have, for example, a Religion Forum, and then get upset when I express my understanding of Scripture in the correct forum. Makes no sense to me.
Ahhh...I kinda remember you now...you were an elevator operator (or something similar), right?

Plus you were a kinda demented "believer", quite worthy of being banned...
warning us poor souls that the end was surely approaching fast...