Among them, common factor method, formula method, grouping decomposition method and cross multiplication are extracted. There are also split addition method, undetermined coefficient method, binary multiplication method, rotational symmetry method and so on.
Conceptual analysis
Among them, a natural number with a divisor greater than 1 is composed of several natural numbers, and 1 cannot be subdivided. 0 is a special natural number, which does not contain the units of natural numbers and does not need to be decomposed. Factorization is to write a positive integer as the product of several divisors, which is of great significance in algebra, cryptography, computational complexity theory and quantum computer.
Among them, the questions are novel, rich in content and easy to understand, including oral calculation, vertical calculation and off-line calculation, so that children can master the essentials of calculation and help preschool children learn oral calculation easily.