The tailor looked at the rich man and said, "Yes."
Seeing that he answered so readily, the rich man thought that the tailor must have taken advantage of it, so he asked, "Do you make three hats?"
The tailor still said cheerfully, "Good!"
At this time, the rich man was more confused and muttered, "What a nice cloth! Can I make four pieces?"
"ok!" The tailor answered quickly.
After some contest, the rich man finally asked, "Can I make a hat of 10?"
The tailor hesitated for a moment, then looked at the rich man and said slowly, "Yes." At this time, the rich man was relieved.
I think it will be cheaper for a tailor if this cloth is only made into a hat. Look! This won't let me say 10 top.
How clever I am! Hey, hey. ...
A few days later, the rich man went to the tailor's to get his hat. As soon as he saw it, he was blindsided: 10 hat is too small.
It's on your finger!
After hearing the story, the students burst into laughter. So I followed the clue and asked two questions:
"What are you laughing at?"
"Why did the tailor say that the hat of 1 can be made of the same cloth, and the hat of 2 can be made of 3, 4 and 5 hats? ...
10 top? "
Through such questions, students' desire to express themselves is aroused, and they are scrambling to express their views:
"The amount of cloth used for each hat × the number of hats = the total amount of cloth. Because the size of this cloth remains the same, there are many hats made, and tailors can cut them, but each hat is smaller. "
Through this story, the concept of inverse proportion surfaced, and then I guided the situation: "The relationship between several quantities like this is called' inverse proportion relationship'. Do you still find out the quantity with similar relationship? " Students have cited such examples as "the slower you walk (the faster you go), the more you spend (the less you spend)" and "the more you transport a pile of goods at a time, the less you transport (the more you transport)".