Example 2: floors also use positive and negative numbers. For example, in a shopping mall with underground parking, we will eat on the third floor and park on the first floor, which is actually a positive and negative application.
Positive number is a mathematical term. Numbers greater than 0 are called positive numbers, and 0 itself is not a positive number. Positive numbers and negative numbers represent quantities with opposite meanings. Positive numbers are usually preceded by a "+"symbol, which can usually be omitted.
Negative number is a mathematical term. Numbers less than 0 are called negative numbers, and negative numbers and positive numbers represent quantities with opposite meanings. Negative numbers are marked with a negative sign (that is, equivalent to a negative sign).
Some basic information about positive numbers:
Positive numbers are positive real numbers, including positive integers, positive fractions (including positive decimals) and positive irrational numbers; Positive numbers do not include 0, which is neither positive nor negative, and anything greater than 0 is positive; If all positive numbers are greater than zero, then all positive numbers are greater than negative numbers; There is neither a maximum number nor a minimum number in positive numbers.
Some basic information about negative numbers:
If all negative numbers are less than zero, then all negative numbers are less than positive numbers; Negative numbers have neither minimum number nor maximum number; The minus sign before a negative number is equal to the absolute value of the negative number.
Extended data:
The origin of positive and negative numbers:
According to historical records, as early as 2000 years ago, China had the concept of positive and negative numbers and mastered the arithmetic of positive and negative numbers. When people calculate, they use some small bamboo sticks to put out various figures to calculate.
Liu Hui, a scholar in the Three Kingdoms period in China, first gave a method to distinguish positive numbers from negative numbers. He said: the front is red and the negative is black; Otherwise, skew is different, that is to say, the number of red stick pendulum represents positive number, and the number of black stick pendulum represents negative number; You can also use a stick with an oblique pendulum to represent negative numbers, and a stick with a positive pendulum to represent positive numbers.
Nine Chapters Arithmetic, a famous ancient mathematical monograph in China, first put forward the law of addition and subtraction of positive and negative numbers: positive and negative numbers say: the same name is divided, different names are beneficial, positive and negative; Its synonyms are divided, the same name is beneficial, nothing is positive, nothing is negative. Here, the name is a number, except subtraction, mutual benefit and division are the absolute values of two numbers, and nothing is zero.
References:
Positive number-Baidu Encyclopedia
Negative number-Baidu Encyclopedia