Helping You Learn Math - A Gift from Academician Zhang Jingzhong for Children (Latest Version)

Author: Zhang Jingzhong
Publisher:
Publish Date: 2003-04-01
Features: The commutative law in arithmetic is just as useful in daily life. However, you can't misuse it either. The story of monkeys eating chestnuts is, of course, made up and not a factual account. But the zookeeper who feeds the animals knows that when feeding pigs, one should first give them roughage and then add concentrated feed to make them enjoy their meal more, so they can eat well, sleep soundly, and be in good health. The commutative law doesn't hold here. There are also some things whose order cannot be exchanged at all. Putting on socks before shoes is correct. But what if you put on shoes before socks? It would look quite strange. Unscrewing a pen cap, filling it with ink, and then writing is correct. The reverse is impossible.
The content of this book: The commutative law in arithmetic is just as useful in daily life. However, you can't misuse it either. The story of monkeys eating chestnuts is, of course, made up and not a factual account. But the zookeeper who feeds the animals knows that when feeding pigs, one should first give them roughage and then add concentrated feed to make them enjoy their meal more, so they can eat well, sleep soundly, and be in good health. The commutative law doesn't hold here. There are also some things whose order cannot be exchanged at all. Putting on socks before shoes is correct. But what if you put on shoes before socks? It would look quite strange. Unscrewing a pen cap, filling it with ink, and then writing is correct. The reverse is impossible.