One PDF sheet of math, one PDF sheet of writing. On every sheet, you can condense two pages into it.
1. writing
two pages of writing condensed into one PDF sheet. I'd suggest you google "2nd grade writing prompt", and find open ended prompt such as "what if I could fly". Also, it is common to have the child draw a picture about the topic and then write about it. So on your writing PDF sheet you'd have a picture on one side and the writing on the other side.
2. For math sheets, same thing, two pages of math puzzles.
Google math competition 2nd grade questions. Don't pick the multiple choice, pick questions that the child can show multiple step reasoning, don't pick questions that merely fill in a number or a shape.
A good sample would be: Kevin is 2 years younger than Anna. Lisa is one year younger than Kevin. Lisa is 6 years old. How old is Anna?
Make your child show the thinking process. If he/she writes poorly, you can use pdf editor to neatly type out his writing so reviewer can see easily.
3. Do one sample on every child's day off. After Thanksgiving you would have a few work samples. Pick the best and finish your package by 12/1. Send to AART, who will provide feedback (not on substance, but on format or legibility), and fix and submit again before 12/15.