It's warm and cold, and it's the season of school. When school started, teachers got busy again, and began to study textbooks and actively explore teaching. Well, some teachers sent us the problems they encountered when preparing lessons.

To this end, we specially consulted Mr. Cui Haijiang, a primary school mathematics researcher at Hebei Institute of Educational Sciences, and answered your questions and doubts professionally.

Problem one

When teaching the first chapter "position" of Hebei education textbook "Mathematics", there is such an exercise:

The teachers are puzzled: the second sub-question of the second question asks the little boy, how many people are there on his left? Does "left" here mean "the observer's left" or "the boy's left hand"? From the observer's point of view, there should be five people on the boy's left; If you count from the little boy's left, there are only two people.

Teacher Cui:

Left and right. As long as the protagonist in the picture doesn't say "who is my left and right, how many people are there", the left and right are determined with the observer as a reference.

Therefore, there are five people on the left of the little boy.

Question 2

A teacher responded that he didn't know how to solve the exercise 1 in the second chapter of the second volume of the sixth grade mathematics textbook of Hebei Education Edition.

Teacher Cui:

People's Education Edition and Hebei Education Edition all use some materials from life, such as chess, Go, movies and so on. Although these are helpful for students to understand the meaning of number pairs (using two numbers to determine the position of a point), they are different from the rectangular coordinate system in junior high school, especially in cinemas with odd and even seats. Therefore, this part of the content requires students to write several pairs, only to examine whether students know "write columns before writing rows" After all, it is not the same as the real rectangular coordinate system.

So, just like the example in the book, write columns first, then rows. The positions of the characters in the movie titles in the cinema are paired as (5, 12).

Question 3

When a teacher was teaching addition and subtraction, he found that many students failed the exam and were very anxious. They don't know how to improve their computing power.

Teacher Cui:

The formation of computing ability needs a process, so teachers should not worry. Usually, I practice more in class (driving a train, oral arithmetic competition, etc.). ), and we can also guide the game. Give each person a few digital cards. Two people can compare the sizes and tell the formulas and results. Whoever talks more wins. But don't arrange a lot of oral arithmetic exercises for students to write after class, which is not effective.