1 and carry addition within 20: look at large numbers, divide them into decimals, round them to ten, and add the fractions. Master the "ten-point method" and advocate the "recursive method". )
2, abdication subtraction within 20: abdication subtraction within 20, oral calculation method and simple. Ten people return one, one person makes up, and the writing is accurate and fast.
3, the meaning of addition, vertical calculation: two numbers are added, and the result of the addition is called sum. Don't forget the numbers on the right, one for every ten.
4, two-digit multiplication: two-digit multiplication is not difficult, there are three points in the calculation process: you must first calculate the multiplier and then multiply it by ten digits. The last digit of the product is the key and must be opposite to the ten digits; After the two products are added up, calculate the number of layers in your mind.
5, two-digit division: divide by two digits to see two digits, two digits are not enough to divide by three digits. Divide the quotient, the remainder is less than the divisor, and then divide by the next digit. The trial commercial law should be flexible, master the "rounding" method, master the "comparison method with the same business" and understand the "semi-definite commercial law", which is not enough to divide the business into nine or eight. (where: same head, less high position 1)
6. The significance of subtraction vertical calculation: from large to small, the result of subtraction is called difference. Digital alignment starts from the right, and when it is not enough, take the front position.
7, mixed operation: carefully get the formula, first calculate the multiplication and division and then add alkali. When you encounter brackets, you should count them first, and the application rules should be changed. There are some data to memorize and skills to master.
8. Decimal addition and subtraction: Decimal addition and subtraction calculation questions are aligned in points. An algorithm is like calculating an integer. After the calculation, move the point down.
9. The sum and difference of two numbers are known. Find these two numbers: sum plus difference increase; Divided by 2, it is big; And subtract the difference, the smaller the reduction; Divided by 2, it is small.
10, difference ratio problem (difference multiple problem): I have more than you, and multiple is cause and effect. Actual difference of numerator, multiple difference of denominator. Double the quotient and multiply it by their respective multiples to find two numbers.
Primary school mathematics
Primary school mathematics is to teach children a series of knowledge about number, four operations, the calculation formula of figure and length, unit conversion and so on through textbooks, which lays a good mathematical foundation for junior high school and daily life calculation. Frieden Noel, a Dutch educator, said: "Mathematics comes from reality and must be rooted in reality and applied to reality."
Indeed, modern mathematics requires us to observe the world from a mathematical perspective and explain the world in mathematical language. Judging from the mathematics learning psychology of primary school students, the learning process of students is not a passive absorption process, but a reconstruction process based on existing knowledge and experience.
Therefore, learning while doing and learning while playing will make children learn more actively. From our educational goal, while imparting knowledge, we should pay more attention to cultivating students' comprehensive ability of observation, analysis and application.