Can't ordinary people do mental arithmetic with three digits × two digits? /kloc-in 0/5, my cousin was the top student in the senior high school entrance examination in mountainous counties, and she c

Can't ordinary people do mental arithmetic with three digits × two digits? /kloc-in 0/5, my cousin was the top student in the senior high school entrance examination in mountainous counties, and she can mentally calculate 56×895. I am the provincial capital. Why not? Because there is no correct thinking, there are different algorithms for calculation at all times and all over the world, among which China's abacus mental arithmetic can easily complete this calculation, and it is very fast. For example, for this problem, change the order first, 895*56, first 895*5=4475, then 895*6=5370, and finally add 50 120. Because children who have learned abacus mental arithmetic can imagine the calculation of numbers as an abacus in their minds, and the middle process is recorded in their minds like an abacus, and finally the correct result is obtained.