My ds8 is in 3rd; he had this real rough spot at the beginning where they were reviewing math facts and 2nd grade or earlier concepts. It was pretty discouraging for him; he wouldn't do the work, or it would take forever and be very frustrating to all involved.
He finally came up with some pretty funny ways of 'showing' his work on the simpler stuff. At last they are hitting some new areas, probability, for instance and he is cruising along, although in my opinion not being stretched. (still waiting on some more math testing for additional differentiation for him)
He brought home a fairly tricky 6 page worksheet on probability and had gotten the whole thing correct.

One way he has of spicing things up is to create a code for parts of what he will be writing, like a head in a circle for 1/4, and a different shape or picture in a circle for 1/2. Then he will use these new symbols when writing 5 1/4 or whatever. He gives the teacher a key at the top of his paper...
fwiw.