绝对值是初中数学中的一个重要概念,它比较抽象,所以是学习中的一个难点.同学们要熟练掌握绝对值的知识,并注意以下三点.一、要正确理解绝对值的意义1.几何意义:在数轴上,表示数a的点到原点的距离叫做数a的绝对值,记作|a|.如图1,数轴上表示-4的点到原点的距离是4,因此-4的绝对值是4,记作|-4|=4;数轴上表示4的点到原点的距离是4,因此4的绝对值是4,记作|4|=4:数轴上表示0的点到原点的 Absolute value is an important concept in junior high school mathematics, it is more abstract, so it is a difficult point in learning.Students should master the knowledge of absolute value, and pay attention to the following three points: First, we must correctly understand the meaning of absolute value. Geometrical meaning: On the number axis, the distance from the origin that represents the number a is called the absolute value of the number a and is written as | a |. As shown in Figure 1, the distance from the origin to the point -4 on the digital axis is 4, so -4 The absolute value of 4 is 4, which is recorded as | -4 | = 4; the distance from the origin to the point representing 4 on the number axis is 4, so the absolute value of 4 is 4, which is recorded as | 4 | = 4: To the origin