"How many pieces of candy are there" is the first lesson of Unit 3 in the first volume of Grade Two. The teaching of this lesson is to make students realize the counting in daily life and often use the calculation of adding the same addend. The simple way to understand this addition is to learn multiplication.
The teaching goal of this lesson is to experience the abstract process of the addition formula of the same addend in combination with the specific situation of counting, so that students can understand what is the same addend and what is the same addend. Feel the connection between this operation and daily life and realize the necessity of learning multiplication; Instruct students to count the number of randomly stacked objects by different methods (pile by pile or row by row, or column by column), and list different addition formulas accordingly; Let students know that it is easier to express the same addend by multiplication formula.
In this lesson, starting from students' counting experience and skills, I asked students to abstract the formula of adding the same addend from the counting problem. When students report the counting methods, I mainly instruct the horizontal and vertical counting methods, and list the corresponding addition formulas according to different counting methods. Then the teacher guides each student to observe each formula, tell the similarities of these formulas, and understand what is the same addend and what is the number of the same addend. In teaching, we should guide students to analyze and compare problems, observe and understand laws, describe and explain conclusions, and cultivate students' mathematical thinking ability. Through a series of counting examples, students are trained to use what they have learned to solve practical problems and inspire their confidence in learning mathematics.
After this lesson, I found that all the students can write some addition formulas of several objects with the same addend, and they can also vaguely write the addition formulas into multiplication formulas, but some students still don't know the number of the same addend and the same addend, which shows that they haven't really mastered the arithmetic of holding multiplication and need to continue to explain it in the next lesson.