Theory:

     “There, there, now, don’t begin that groaning again. Open your mouth. Well. Your tooth is loose, but you’re not going to die from that. Mary, get me a silk thread, and a chunk of fire out of the kitchen.”
 
     Tom said, “Oh, please, auntie, don’t pull it out. It don’t hurt anymore. I wish I may never stir if it does. Please don’t, auntie. I don’t want to stay home from school.”
 
     “Oh, you don’t, don’t you? So all this row was because you thought you’d get to stay home from school and go fishing? Tom, Tom, I love you so, and you seem to try every way you can to break my old heart with your mischief.” By this time the dental instruments were ready. The old lady made one end of the silk thread fast to Tom’s tooth with a loop and tied the other to the bedpost. Then she caught hold of the chunk of fire and suddenly pushed it almost into the boy’s face. The tooth was hanging loosely by the bedpost, now.
Explanation:
 
By this time, Aunt Polly now understood everything. She asked Tom to stop crying and that he would not die out of toothache. She told Mary to get silk thread and some fire out of the kitchen so that she can pull the tooth out.
 
Tom knew that Aunt Polly understood his tricks and said that his toothache has gone and there is no need to pull the tooth out. He was also eager to go to school.
  
Aunt Polly made it clear to everyone that Tom was doing all these to stay home and go fishing. She suggested that Tom was taking advantage of her love. Meanwhile, she had everything to pull Tom's teeth out. She tied one end to Tom's teeth and another to the bedpost and slowly kept the fire near him. Before he could move, he saw his tooth loosely hanging.
 
Meanings of difficult words:
 
Numbers
Word
Meanings
1.
Bedpost
 Any of the four upright supports of a bedstead.
2.
Chunk
Thick piece of something.
Reference:
State Council of Educational Research and Training (2018). Term-1 English Standard-7. On Monday morning - Adapted from The Adventures of Tom Sawyer by Mark Twain (pp. 18-21). Published by the Tamil Nadu Textbook and Educational Services Corporation.