In subtraction, when one bit of the minuend is less than the value of the corresponding bit of the minuend, it is necessary to borrow. Borrowing refers to borrowing 1 from high order to low order for subtraction. Borrowing can make subtraction operation smoother and reduce the probability of mistakes. The significance of borrowing is to ensure the correctness of subtraction and enable us to calculate mathematical problems more accurately.

Borrowing is very common and easy to master in subtraction. For example, the subtraction operation of 867-458 needs borrowing, that is, borrowing from 7 in the hundredth place 1 becomes 6, and then changing the 6 in the tenth place into 5, and finally getting 409. For another example, the subtraction operation of 234-79 needs borrowing twice, that is, it changes from the third borrowing 1 in the tenth place to 2, then from the hundredth borrowing 1 to 0, and finally gets 1 55. The practical application of borrowing money can not only help us calculate mathematical problems more accurately, but also provide us with mathematical tools in our work and life.

Metonymy is not only the basic operation of mathematics, but also the thinking ability we should have. Use education to encourage children to think positively, find problems and seek solutions. It can help to cultivate children's logical thinking ability and problem analysis ability, as well as their perseverance and patience. In life, when encountering problems, we can draw inspiration from the idea of borrowing money, effectively solve problems and achieve success.