Personally, I don't approve of learning abacus mental arithmetic before the conceptual foundation of the number of children is solid, and the learning method of abacus mental arithmetic is different from that of primary school mathematics (after learning abacus mental arithmetic, you will find that the mathematical method of abacus mental arithmetic in primary school is completely abandoned and started from scratch), which will not help much in mathematics learning after entering school. My heart says this is because there are practical examples around me, and the troubles brought by abacus mental arithmetic far outweigh its benefits, so I suggest choosing carefully. Even those children who are good at abacus mental arithmetic may not be good at math in primary school, so if children find it difficult to accept it, it may be better to give up.
The mathematical concept of cultivating children can permeate from life, from singing (mouth number) to counting (hand index) to taking numbers according to things, starting from the first number in order and then starting from any number in the middle. In addition, when reading numbers to children, singular and even numbers can be read separately, and gradually children's mathematical concepts will deepen their understanding of the difference between singular and even numbers. Don't underestimate these "boring" ways (but you can also do them in interesting ways), which is very good for laying a good foundation in mathematics.
The above is my personal observation and understanding of children. Let's see what the experts say:
School-age period of learning abacus:
When children are 2~3 years old, they begin to be interested in numbers and have doubts about them. 4~5 years old, the dexterity of fingers increases, and you can play with abacus, but at this time, because there is no basic concept of addition, subtraction, multiplication and division, the effect of learning abacus will not be ideal. It is more appropriate to learn abacus in the third grade of primary school, because the school has already learned multiplication and division, and I get it.