This problem must be solved as soon as possible, and it will not change until high school forms a habit. The calculation is wrong, which means that the child usually ignores the calculation in his study. Psychologically, I think calculation is a simple matter, just knowing the truth, but I don't know that half of mathematics is calculated while learning thinking. Therefore, first of all, let children pay attention to calculation, develop the habit of calculating any number by themselves, and never rely on calculators and answers. This is cultivated bit by bit in daily life. It seems a small problem, but it is not easy to change it.