In the definition of number axis, each real number can be represented by a point on the number axis, and the distance between different points indicates the size relationship between real numbers. On the number axis, the positive direction represents positive numbers, the negative direction represents negative numbers, and the origin separates positive numbers and negative numbers.
Through the definition of number axis, we can add, subtract, multiply and divide real numbers. For example, if we represent two numbers on the number axis and add them together, we can get their sum by connecting the representative points of the two numbers on the number axis and then moving from the starting point to the end point along the number axis.
The advantage of the definition of number axis is intuitive and easy to understand. It provides a visual tool for mathematical concepts and helps us to better understand the nature of numbers and the relationship between numbers. At the same time, the definition of the number axis also provides a basis for subsequent mathematics learning, such as the comparison of real numbers, absolute values and other concepts can be explained and understood according to the number axis.
Matters needing attention in the use of number axis
1. Clear proportion: It is very important to determine the proportion when drawing the number axis. In order to ensure the uniform distribution of scales, the appropriate scale interval can be selected according to the data range. If the data range is large, you can use a larger scale interval to avoid the number axis being too long. On the contrary, if the data range is small, a smaller scale interval can be used to represent the numerical size more accurately. In addition, you can also consider using different precision scales, such as integer scale or decimal scale, and choose according to the specific situation.
2. Mark the starting point and ending point: After the scale is determined, mark the starting point and ending point on the number axis. The starting point is usually 0, and the ending point corresponds to the maximum or minimum value of the data.
3. Mark data points: mark the specific position of the given data on the number axis. It can be represented by points, arrows or vertical line segments. Make sure that the labels are clearly visible and accurately represent the size of the data.