A little more background.
PTC acquired Mathsoft (and with that: Mathcad) over 10 years ago. Very soon after that, they decided that Mathcad-as-we-knew-it was not the way to go. They started development of 'Mathcad Prime'. Prime brought a few improvements over Mathcad. I can think of three:
1. Mixed units in vectors & matrices,
2. Automatic variable/unit/function/constant labelling (though brings some problems every now and then),
3. Prime express. You get to use a limited version of the full Prime for free, for ever (PTC promise).
However Prime results in an enormous penalty in speed (starts slow, equation entering is slow, calculation is slow), functionality (lacking features that Mathcad had) and price (you get to pay a yearly subscription, you cannot get a perpetual license for a lifetime anymore). Some bugs reported for Prime 3.1 are still not fixed.
In over 10 years, PTC have managed to bring out 5 'major releases' of Prime, where the new features included with each release got smaller over time. I've seen PTC promising more than it actually delivers, and it spits out later than it promises. The difference between Prime 5 and 4 is a third-party 2D plotting tool that uses a different paradigm compared to the 'native' plotting tool.
If you want a luxury numerical calculator, with reasonable 2D plotting facility, then Prime Express is OK. Do not expect symbolics, programming, solve blocks (for solving sets of equations or numerically solving differential equations), or really fancy mathematical functions such as: the Gamma function, Re and Im to get real and imaginary parts of complex values, mean (average of the elements of a vector), stdev, and many other statistical functions to name a few.
Personally I think that students, and especially in technical disciplines, should get to know tools like Mathcad during their education so that they know it exists, and what kind of possibilities they can expect from such tools. (I think that graphical calculator devices are old-fashioned.). Mathcad (yes, Prime too) is the tool with the lowest learning curve compared to Mathematica and Maple (and I don't compare it to Matlab, because that is a programming language). There's one other potential alternative: Smath Studio, free and much like Mathcad. It can even read Mathcad 15 files...to some extent. Your's is too complicated.
SO, there is
In decreasing order of functionality (why the hell call it Prime if it is less "powerful" than the regular one.
Because PTC think that their version of Mathcad, Mathcad Prime, is better than the version developed by Mathsoft (which they purchased), everything up to and including Mathcad 15. Almost everybody that uses the Mathsoft version disagrees. There are a few things Prime does that 15 does not (e.g. mixed units in arrays), but overall it is much less capable. PTC also wants to force everyone to upgrade, even if they don't need the new capabilities, which is why a later version cannot save to an earlier version format. To be certain that you are really forced into that, now you can only get Prime on a subscription basis, so if you don't pay every year you lose access to your own work. A sort of legal ransomware. That was really the last straw for me, and I gave up on Mathcad. That's why I dropped out of sight here (apart from a very occasional appearance, like now).
I now use SMath Studio (SMath Studio) when possible, which has an interface that is very similar to Mathcad, and revert to Mathcad 15 if I need to do something it can't handle. It's not as powerful as Mathcad 15, but it's a lot more powerful than Mathcad Prime Express (in particular, it can do symbolic math, as well as a number of other things that were deliberately crippled in Express). I would say that it's a toss up when compared to Prime. In some respects it's better then Prime, in other respects it's worse. It can read some Mathcad files, but only .xmcd format (which you can create from .xmcdz by renaming it to .zip, unzipping it, and renaming it to .xmcd), and unfortunately, not your example. It is completely free. And, you can now get it on Android and iPhone! Take that, PTC! I haven't played with the Android version much yet, but it certainly beats Mathcad on Andoid, because that doesn't exist at all!
2. I have tried to rejuvenate an old file for me to give to the students (the file I sent you). Your conversion came back as very buggy when opened with Prime. I am not sure if it would have read properly from the regular version.
The version you sent looked quite OK in Mathcad 15.
The red lines and arrows you see in the converted file are just annotations inserted by the converted indicating that here and there things may look different than they used to look in Mathcad. You can delete those annotation via the menu (Input/output - delete annotations).
The converter is known to fail when it comes to headers an footers and you will have to rebuild them on your own with the limited possibilities in Prime.
Furthermore the converter in no way respects the page sizes so its normal for the converter to make pagebreaks in the wild and you will have a lot of fun to repair that manually.
Worst of all as you may already have noticed is that the converter just inserts a picture of the original math region if the function is not available in Prime (like the gradient operator) or the syntax is not supported (like in some of your matrix multiplications).
Thats all what I was talking about when I wrote that the file would need some post processing and rework. Admittedly the "some" was a big understatement.
IMHO you should not expose your students to Prime Express or Mathcad. Mathcad as we know it will not be supported anymore sooner or later and Prime will never live up to a useful tool for engineers the next decades as the "development" so far has shown.
So if the very limited Prime Express looks useful to you - use it, but you may want to rather give SMath Studio a try, after all its free.
And then you may have a look what tools the companies your students will go to are using - maybe you'll end up with MatLab and/or Maple, maybe with something else.
P.S.: I attach a PDF print of the original file you posted just to show that it looked OK in Mathcad 15,
While the conversion of this sheet to Prime 4 may work, I think you will be left with some problems.
I see that the sheet references a WaterSteamPro .mcd sheet that would also need to be converted.
I can't open that referenced sheet. It's not accessible (by me) at the indicated location (it may be for you).
I suggest you contact ValeryOchkov to find out if it would work at all.
1. do not understand why the company change the format again and again. this is the second time they change
2. and the import function does not wok, which needs Mathcad 15. However mathcad 15 cannot be installed in my window 10.
feel very disappointed with this.