For example, 1: You can put out several different numbers, such as 9, 18, 27, 36, 45, 54, 63, 72, 8 1 90. The largest number is 90 and the smallest number is 9.

For example, 2: The number that three circles can pose is 80, and the sum of one digit and ten digits is 8+0=8.

Add:

(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".

3+2 = 5 and Apple are popular choices in textbooks.

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.