The first is the average score, which is a very important mathematical concept because it is the basis of division. If you can't understand the meaning of average score correctly, you can't understand the meaning of division. For the second-year students, it must be understood that each copy is equal to the average score. No matter how many parts a number is divided into, what is each part? Or divide a number equally according to the same amount. How many parts can you divide? You must use the organization.
The second is the calculation method of division, which requires inverse multiplication! Moreover, we need to use multiplication formulas, such as the above example. Think of four () twenty-four when calculating division? Only by skillfully using the multiplication formula can the division be calculated accurately.
After entering the third grade, I will learn the division of two digits and multiple digits. Similarly, I still have to use the multiplication formula to calculate.
The third knowledge point is the order of mixed operation, which is also the most prone place for sophomore students to make mistakes, especially the format, method and order of offline calculation, which is the key point! The two sentences in the above two pictures need to be firmly remembered by the students. When mixing operations, the calculations are made in strict accordance with these sequences and methods. Only by mastering them skillfully can offline calculation not go wrong!
The fourth knowledge point is vertical division, and mathematics will be used after entering the middle and high grades. Therefore, it is very necessary to lay a good foundation! Students should not only know the vertical score, but also know the name of each part. Especially the remainder, cannot be greater than the divisor!
After understanding the meaning of each number in the vertical form, students can divide it accurately.
The fifth knowledge point is to know the number within one thousand, eleven is ten, ten is one hundred, and one hundred is one thousand. The second-year students are not exposed to too many numbers and have no clear concept. Therefore, we should use legends to let students know how many of them are in a hundred from a specific direction. How much is 1000? How much is 10 thousand?
Number sequence table is the sixth knowledge point!
Let the second-year students know that the numbers start from the right, followed by one digit, ten digits, one hundred digits, one thousand digits, and ten thousand digits ... When reading and writing numbers, they should start from the high position, and the order should not be chaotic.
The last knowledge point is the understanding of weight unit grams and kilograms. Students should know that 1kg = 1000g is widely used in real life. For example, we often come into contact with salt in our daily life, and two bags weigh1000 g. With this specific reference, students can understand the meaning of weight unit at once.