How many small trees are there? This lesson is the first lesson of Unit 4 in the first volume of Grade Three Mathematics of Beijing Normal University. It is students' further study after learning table multiplication.

In the new teaching, I created a "tree planting" teaching situation for students to talk about known information and ask mathematical questions. When the students put forward a math problem: "How many trees are there in a bundle of three * * * *", I asked the students to explore independently, cooperate and communicate, encouraged them to put forward different calculation methods, and then optimized the calculation methods in the group report and communication.

Students have various algorithms, such as drawing, adding 20+20+20=60 to calculate, and more students directly use the method of covering 0 to calculate. Calculate 2×3=6 and 20×3=60 first, and I will guide the students in time. What does "2" mean? Due to the review before class, students can quickly grasp that "20 is two 10". Therefore, the study of new knowledge is nothing more than that.

For the following "500×3=?" I guide students to summarize the calculation method of "20×3", and then explore "500×3=?" with the method of transfer analogy. The algorithm of. This not only uses the brain, but also saves time and cultivates students' learning ability.

In the teaching of this course, teachers fully respect students, take students as the main body, create a democratic and relaxed learning atmosphere for students, encourage students to explore new knowledge independently, let students actively participate in mathematics learning activities, and personally experience the oral calculation process of multiplying whole ten, whole hundred and a number, so that students' subjective initiative can be fully exerted and their learning enthusiasm and efficiency are high.