Method 1: Do subtraction and want to add. Do the inverse of addition with subtraction and think with addition. For example, 12-8, Xiang 8+() = 12.

Method 2: break the ten methods. For example, 13-7 can be thought as follows: 10-7+3=6.

Method 3: continuous subtraction (commonly used method), such as 13-7. You can think of it this way: 13-3-4=6, which means dividing 7 by 3 and 4.

Method 4: Supplementary method. For example, 13-7 can also be thought like this: 13- 10+3=6.

There are many kinds of oral calculation methods, and how to find the best oral calculation method is the key to improve the speed and accuracy of oral calculation. When practicing, you can review a variety of oral calculation methods with students, so that students can get the best method through comparison.

There are many reasons for children's verbal errors, which can be summarized as follows:

1, psychological reasons

Students' understanding of the event is quite general and not specific enough. They often only pay attention to some independent things, but can't perceive the connections and characteristics between things, so they lack the overall understanding of things. Sometimes when doing oral arithmetic exercises, some students blurt out the answers before they see the numbers or operation symbols clearly.

For example, in the formula, consider "0" as "6" and "+"as "-". In addition, when students calculate some complex problems such as expressions, they will have rejection psychology, which is manifested as extreme impatience, careless examination and calculation, which will lead to a slip of the tongue.

2. The influence of non-intellectual factors.

The first-year students are too young to realize the importance of correct oral calculation. I am not interested in verbal arithmetic, and it is more troublesome to repeat training mechanically, so I talk nonsense without thinking. Even the best study habits are not fully developed, and you can't concentrate on doing oral calculations when doing homework; Irregular writing, scrawled handwriting, and difficulty in checking calculation after calculation are all causes of calculation errors.