**Math formula**– In this material, I will discuss about

**middle school math formula**namely the discourse of numbers. Numbers themselves can be interpreted as an idea that has abnormal properties and can provide information about the number of a set of objects. Numbers are usually expressed in numeric form. In mathematics, there are various forms of numbers. Let’s study these numbers one by one.

### **Junior High School math formulas about numbers**

The original numbers are the set of positive numbers that consist of numbers other than zero (0).

For example: {1,2,3,4,5,6,7,8,9,1,0,11,12,…}

Whole numbers are a set of integers that are positive (not negative) and start from zero.

For example: {0.1.2.3.4.5.6.7.8.9,…}

Integers are a mixed set of whole numbers {0,1,2,3,4,5,…} And also the negative form of these numbers {-1,-2,-3,-4,-5,.. .} Since -0 is equal to 0 then it is enough to just write 0 in the set of integers.

If a, b, and c are integers, then the addition property is:

If a, b, and c are integers, then their multiplication property is:

The operations of addition and multiplication in the set of integers have distributive properties, namely:

Prime numbers are the set of original numbers that have only 2 factors, 1 and the number itself. The opposite of prime numbers is composite numbers.

For example, 3 is a prime number because 3 only has 2 factors (1 and 3) meaning 3 can only be divided by 1 and 3 and does not produce a fraction. Unlike the number 8, the number 8 is not a prime number because it has more than 2 factors, namely 1, 2, 4, and 8. 1 is also not included in a prime number because it only has one factor, namely the number 1. itself.

The first 20 prime numbers are:

2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 47, 53, 59, 61, 67, 71, 73, …

You also need to know that the number 2 is the only prime number that is even.

Real numbers are a group of numbers that can be written in decimal form, such as 1.3425 or 8.8452637. Real numbers consist of rational and irrational numbers.

**Rational number **is a real number which we can write in the form a/b where a and b are integers where b≠0. Examples are 42 and 123/129.

**irrational number **are real numbers other than rational numbers, for example: (2,34…) and 2

Imaginary numbers represent numbers other than real numbers, such as -1. -1 is usually symbolized by the character

*“i”*so -3 = 3*i*