The basic concept of the square matrix problem, the meaning of the parser, represents a square. According to the layout of the square, the number of people in the team is the same. It is generally a large number when investigating, and the result is also a large number, which cannot be effectively solved by enumeration. Therefore, the knowledge points of this topic exam are also obvious, that is, memorizing formulas and adding a little reasoning is simple and troublesome. The concept of sharing can be verified by enumerating small numbers in order to further deepen the influence.
Mathematical calculation skills in primary schools
1, percentage calculation
When calculating the percentage, in fact, "%"can offset two zeros. For example, when calculating "300 12%", you only need to remove the two zeros after "300" to cross out "%",leaving "3x 12=36". Isn't that easy?
2. Add and subtract scores
Generally speaking, find the least common multiple of two denominators and then calculate. But in fact, just draw a butterfly on the formula. Multiply the butterfly wings and write them in the antenna. Adding them together is the numerator of the answer, and then multiplying the denominator with each other is the denominator of the answer. Subtraction is the same method, except that the number in the antenna is changed to subtraction.
3. Multiply two digits by 1 1.
Multiply any two digits by 1 1, separate the ten digits from the single digits, and insert the sum of the ten digits and the single digits in the middle to easily calculate the answer.