My DS9 in 2nd grade, last year knew all his spelling words the 1st day he brought them home. His spelling for the year was over 100% because he also got almost all of the teachers bonus words too. Luckily, his teacher had chalkboard spelling competions he wanted to win. The fastest student with the correct word would win. He studied his words even though they were too easy because the teacher made the practice meaningful with the competion.
When my son brought home his spelling words they were on a page with some stories. He would circle a few of the bigger words and ask me to quiz him for a challenge.
We would also look up a word from his list once a week in the dictionary for definitions.
My advice for anyone wanting to try these ideas;
I think it's better to tell students it would feel good to do this and be challenged. But this is extra work and it should not be pushed. Encourage the student to push themselves when they need it.
Talk to the teacher or gifted teacher, she may have ideas for Challenging him. My son brings in reading, and extra Math workbooks (instead of coloring books) and does independent studies when his work is done early. They also gave his readers that were more on his level.
You are so luck to get an hour a day in gifted program. We only get 20mins. twice a week.
good luck. I hope this is helpful.
