Spelling Difficulties in Third-Grade

My son, a third-grader, has a difficult time spelling many of the words he uses in his daily work. However, he does great on his weekly spelling tests -- all "A" grades. Can your explain this? How can I help him? -- No Speller
Answer: The words that children really need to learn how to spell are the ones that they use in their daily writing. It is quite possible that the words your son is learning on the weekly spelling tests simply aren't the ones he needs the most for his daily work.
Have you investigated what words your son is misspelling on his assignments? There are probably a number of words that he consistently spells incorrectly. Work with his teacher in identifying this list of words. It would be great if a few of these words could be part of the weekly spelling test. If this isn't possible, then you need to step up to the plate and help him learn these words.
Here's what you need to do. Select the 25 words that he misspells most often, and work on them first. On Monday, test him on five of these words. Then spell the words orally for him and have him write the ones he missed correctly. Once this is done, give him the same quiz again and have him correct any missed words. Follow the same steps on Wednesday and Friday. Work with five new words the next week and so on. After your son has worked with all 25 words, quiz him on all the words for a week as a review. Then quiz him again on these words in 10, 20 and 30 days. Hopefully, this will help him master these words, unless his spelling problems are related to a learning disability.
Incidentally, the more your son reads, the more words he will see spelled correctly. Plus, playing spelling word games (Boggle and Scrabble) will give him additional practice in spelling words correctly.