Introduction to addition.
Addition is one of the four basic operations, which refers to the calculation of combining two or more numbers and quantities into one number and quantity. The symbol of addition is the plus sign "+". Connect items with a plus sign when adding.
Addition (usually indicated by the plus sign "+") is one of the four basic arithmetic operations, and the others are subtraction, multiplication and division. For example, in the picture below, * * * has a combination of three apples and two apples, and * * * counts as five apples. This observation is equivalent to the mathematical expression 3+2=5, that is, "3 plus 2 equals 5".
In addition to calculating fruits, you can also calculate other physical objects. Using system generalization, addition can also be defined on more abstract quantities, such as integers, rational numbers, real numbers and complex numbers, and other abstract objects, such as vectors and matrices. In arithmetic, the addition rules involving fractions and negative numbers are designed.
Addition has several important properties. It is interchangeable, which means that the order is not important, it is interrelated, which means that when more than two numbers are added, the order in which the addition is performed is not important. Repeatedly adding 1 is the same as counting; Adding 0 will not change the result. The method also follows related operations such as subtraction and multiplication.
Step 2 explain
Addition has been used to establish countless physical processes. Even in the simple case of adding natural numbers, there are many possible explanations and more intuitive expressions. Perhaps the most basic explanation of addition lies in combination: when two or more disjoint sets are combined into a single set, the number of objects in the single set is the sum of the number of objects in the original set.
This explanation is easy to imagine. It is also suitable for advanced mathematics; For a strict definition of its excitation, see the following natural numbers. One possible solution is to consider a set of easily divisible objects, such as pies. Rods can not only form a set of rods, but also connect rods together, which explains another concept of addition: not adding rods, but adding the lengths of rods.