I think there will be a real conflict at first. It is easy for students to use the speed algorithm in kindergarten when calculating, but after a period of running-in, most students can adapt. Because when calculating carry addition, the number of fingers is calculated by very few people after all. Moreover, the fast algorithm in kindergarten is actually a very fast calculation method, but there is no room for them to study further in primary school. It's a pity to think about it. Therefore, doing a good job of "gathering teenagers" is actually a very real activity, which has benefited me a lot.