It is not recommended to go through customs clearance. Oral math is the first and second volumes of primary school mathematics oral math problem card 1-6 grade. It is a synchronous exercise book for oral math and mental arithmetic, which improves mathematical computing ability. This workbook is closely followed by the textbook, basic course 1.2 page. However, the number of questions is very small, and one page can be written in three minutes. The key is that the questions are more complicated, not just verbal calculation, but also contact and picture presentation. There are only a few questions on a page, which actually has no effect. You might as well buy a whole page to practice. The calculation of small talents is the addition and subtraction of three numbers, with brackets, which is obviously more difficult. I recommend buying this.

Oral calculation is one of the important contents in mathematics knowledge learning, especially the oral calculation within 20 is particularly important. Mathematics is gymnastics of thinking, and oral arithmetic training is an important part of gymnastics. In oral arithmetic training, students should carry out complex thinking activities in an instant and "decompose, transform, change and reorganize" the test questions to achieve quick and accurate answers. The task of oral arithmetic training is to cultivate students' computing ability, thinking ability, reaction ability and the ability to use both hands, brain and mouth, so as to establish a new model. How to improve students' mathematical calculation ability and improve the accuracy and correctness of calculation is a problem that we all have to solve together. In primary school mathematics, the calculation of addition and subtraction runs through the whole primary school mathematics study, and the addition and subtraction within 20 is the key initial stage of lower grades, which has a far-reaching impact on students' further study in the future. Teaching practice tells us that any complex problem is composed of a simple one. Whether it is two-digit addition and subtraction, three-digit addition and subtraction, or even multi-digit addition and subtraction, their basis is "addition and subtraction within 20"