Some short stories may interfere with the teaching process as teachers design questions to attract students' attention. For example, during "Mixed Function of Addition and Subtraction," the authors introduce a short story: "A group of monkeys play through the well. A breeze blows a monkey cap into the well, and greets 18 children." Remove the caps from the tree one by one. However, the 4 monkeys didn't climb the tree, so they picked the hat and the teacher might ask: Is it just a few monkeys bringing a hat to the tree? "Then the teacher continued to ask," If there are 14?