TITLE: Entry systems for math that are simpler than LaTeX
QUESTION [7 upvotes]: This may belong in Meta.  Please don't say Software Recommendations.  I have yet to receive a meaningful recommendation from that group due to a paucity of other users.
I work with kids whose handwriting is their own worst enemy. (Typically junior and senior high school.  Most already are 10-20 wpm typists)
I'd like to find a way for them to enter algebra  that is keyboard centric (not endlessly dragging and dropping, and nudging symbols) but is more or less WYSIWYG. Unusual symbols may end up be drag and drop, but I would like to be able to, say, derive the quadratic formula without having to recourse to drag and drop.
The editor should make it easy to edit.  I've run into a couple that were 'write only' systems where you couldn't change something.  Much like doing math with a quill pen and india ink.
It needs to be close to as fast as writing by hand for someone who is a touch typist.  It should support cut and paste for bring down parts of an equation that are unchanged.
The closest I've come is FrameMaker, which used ^ to start a superscript _ to start a subscript, and space bounced you out one level.I don't remember the rest.  I no longer have FM so it's moot.
An example of an awful system is the Microsoft equation editor, at least as of 15 years ago.
I would expect such a system to use LaTex under the hood, but it doesn't have to.  A fringe benefit would be the LaTex of the current equation showing up in a sub window, and being able to edit in either.
The symbol set doesn't have to be vast.  Being able to readily handle 2 levels of nested brackets, Equations with fractions.  
I'd like to have a way for them to work out problems that don't proceed linearly down the page.  E.g. a way to do polynomial long division.  
Small matrices.   First course in calculus.
In essence I'm looking for something that does for math what markdown does for writing html.
Anyone know of such a system?
Moderators: I couln't find a tag Latex or interactive math editor.  Adjust tags.  This likely means this is in the wrong SE.  Please advise.

REPLY [2 votes]: You mentioned Microsoft as of 15 years ago. I just opened up Word 2016, and the equation editor there is probably about the level you are after. For example, typing the following input:
y >= 2 + 3 sin(x^3)

produced $$y \geq 2 + 3 \sin(x^3)$$ which is considerably nicer to input than anything LaTeX based.