It sounds very much like your school is using Singapore math for its curriculum. The curriculum is hard at first for most kids to get the idea that there is more than one way to get to an answer, or to solve a problem. While they are in the concrete part of the curriculum, there is a lot of the "write this in 3 or 4 different ways" stuff, it seems really annoying and useless at this point, especially when the child already knows the answer, however, the beauty of this curriculum is that once they are in the habit of looking for the different ways of solving things, or of writing numbers, the pay off is huge in upper elementary and into middle school when the math actually gets harder and needs different perspectives to solve the problem.
I have taught the curriculum and love it because the real outcome of it is that kids acquire a true number sense that allows them be successful in higher level math much more readily than being taught the traditional way where they learn the algorithm and that's it. Having said all of this, I do not have much experience with 2e kids in my math classes. I know my non-2e daughter was frustrated with having to pick just 3 different ways, but we were finally able to convince her that it really didn't matter which ways she wrote down the answers, as long as she picked 3. It may be helpful to ask if she can do math work on graph paper with really large boxes, then she can write 1 number per box and put the +,-,= stuff between them, or make a bunch of papers with the circle pre-drawn on them (they use these V shaped number bonds for a long time in Singapore math).
Good luck.
