course content
On page 132 of the textbook, the questions in example 4, "doing" below example 4 and questions 5 ~ 10 in exercise 30.
Academic goal
Enable students to further master the reasoning process of conversion between area units and deepen their understanding of area units. Cultivate students' reasoning ability.
Teaching focus
Make students further master the conversion between area units.
Teaching difficulties
Understand and master the reasoning process of conversion between area units.
training/teaching aid
tape measure
teaching process
I. Review and Thinking
1, let the students talk about how to calculate the area of a rectangle.
2. Do the following questions and say how to infer.
5 square decimeter = () square centimeter
13m2 = () square decimeter
Second, group cooperation, exploring new knowledge
1, teaching example 4. (Adapting the example, let the students directly measure the length and width of the desk, calculate the area, and then convert between units. )
(1) How many centimeters does the student measure the length and width of the desk? What is the area of the desktop in square centimeters? (Keep the whole hundred square centimeters) How many square decimeters?
(2) Students make calculations, and teachers make judgments according to specific conditions.
(3) Students discuss the reasoning process of converting square centimeters into square decimeters. (100 square centimeter is 1 square decimeter, and there are as many square centimeters as there are square centimeters. )
2. Do the exercises in Example 4 "Doing" below: (Students tell the reasoning process)
500 square centimeters = () square decimeter
4200 square decimeter = () square meters
Third, consolidate the feedback and master the transformation method.
1. Do the fifth question in Exercise 30. Tell me how it is inferred.
2. Do the sixth question in Exercise 30, and let the students talk about the calculation process.
3. Do Exercise 30, Question 7, and find out how many kilograms of celery are collected on average per square meter? What conditions are known? What else do you need? Where is this condition?