1, sort out knowledge points. Before making a mind map, we should first sort out the knowledge points. And when sorting out knowledge points, it is required to be comprehensive. The comprehensive arrangement of knowledge points is to make a complete mind map.
2. Sort out knowledge points, find out the relationship between them, and then extract keywords. Next, after the knowledge points are sorted out completely, it is necessary to sort out the knowledge points.
3. Establish the structure of mind map according to keywords. After the keywords are sorted out, the structure of mind map is established. The so-called structure is the display of the relationship between keywords. According to the relationship between keywords, determine the branch of mind map.
The paper should be placed horizontally, which will be more convenient for drawing and more conducive to the expansion of branches. If the theme is determined, it is suggested to use a central diagram to represent it, so that the brain can easily notice your theme.
Understanding of decimal and addition and subtraction knowledge points;
1, the meaning of decimals: divide a whole into 10, 100, 1000 ... how many parts are decimals, a few percent, a few thousandths ... can be expressed in decimals. One decimal place indicates a few tenths, two decimal places indicate a few percent, and three decimal places indicate a few thousandths.
2. How to compare the sizes of decimals: first compare the integer parts, and then compare decimals, percentiles and thousandths one by one.
3. Align decimal points and add and subtract the same digits. While multiplication is rightmost aligned. Therefore, the counterpoint of decimal addition and subtraction must be distinguished from multiplication.
Subtraction is a mathematical operation.
Represents an operation to remove an object from a collection. Its symbol is the minus sign (? )。 For example, in the picture on the right, there are five? Two apples, five apples, two were taken away, leaving three apples. So 5? 2 = 3。 Subtraction is to remove or reduce physical quantities and abstract quantities with different objects (including negative numbers, fractions, irrational numbers, vectors, decimals, functions and matrices).