Yahoo Answers is shutting down on May 4th, 2021 (Eastern Time) and beginning April 20th, 2021 (Eastern Time) the Yahoo Answers website will be in read-only mode. There will be no changes to other Yahoo properties or services, or your Yahoo account. You can find more information about the Yahoo Answers shutdown and how to download your data on this help page.
Trending News
Number Sense decimal question, need help?
Okay I am trying to help my son with his homework and I can't remember how to do these. It's been awhile since I have. The question is: Place decimal points in these numbers ( 329 913 477 624 ) so that their sum is 519.654
You don't have to give me the answer just how do you figure it out. He has many other problems to do and the book is no help.
3 Answers
- 1 decade agoFavorite Answer
i dont think there is really a way he's supposed to work it out other than trial and error
477 + 32.9 + 9.13 + .624
- back2natureLv 41 decade ago
Hmmm.. interesting to know that there are such practices on number sense.
This is how I guess:
I need a 0.004, last digits are 9, 3, 7, 4. Thus, seems like the only way is to have the 4 alone, i.e. 0.624 while the other three will be more than 1.
Then, need a 0.05, relevant digits are 9, 3, 7, 2 (must have 2). Thus, the only way is 3+2=5, i.e. 9.13.
Next, need a 0.6, relevant digits are 9, 1, 7, 6 (must have 1 and 6). Thus, the only way is 9+1+6=16, i.e. 32.9.
Lastly, need a 9-1 (brought forward from 16 above), relevant digits are 2, 9, 7, 0 (must have 2, 9 and 0). Thus, the only way is 2+9+7+0=18, i.e. 477.
Therefore, the 4 numbers are 32.9+9.13+477+0.624 = 519.654
By the way, the book should not help if the idea is to induce number sense. There should not be any method to be learnt on this. Look at the problem from different angles, think of many possibilities and impossibilities, thus have better sense for the numeric values.
Actually, my first thought was: 913 and 624 are more than 519, so decimal point in them must be make them smaller. However, between 329 and 477, it is not conclusive what should be done. So, I started looking at the problem from a different perspective.
Furthermore, don't stop once you get a solution. The idea here is to think of more ways to work on it. It helps regardless of the ways you thought of work or not.
Source(s): It is such numerical sense that should be taught in mathematics classes rather than methods. - 1 decade ago
I don't really know other than trial and error. I don't think I ever had to do anything like this, and really don't see what the value of the exercise is. Nevertheless, does it say in the instructions that the decimals will all be in different places, for example, one between the first and second numbers, one between the second and third numbers, etc.?
For example,
with four numbers you may have
.1111
1.111
11.11
111.1
I just happened to figure out the one you gave in the example, if you want it, but I really just lucked upon it.
477.0 + 32.9 + 9.13 + .624
Good luck!
