What Is a Prime Number? (Mathematics Lesson)
What Is a Prime Number?A prime number is a number that can be divided by only itself and one.
For example, 5 is a prime number. It can only be divided by 1 and 5.
The prime numbers are:
In a number square, the prime numbers are shaded below:
A prime number must be a whole number greater than 1, which is a natural number.
Because there is not limit to how big a natural number can be, we do not know all the prime numbers!
Here's a dynamic test on prime numbers.
FACTORSFactors are numbers that you multiply together to get another number.
For example, the factors of 6 are 1, 2, 3 and 6, because:
1 × 6 = 6
2 × 3 = 6
For prime numbers, the only factors are 1 and the prime number itself.
The only factors of 5 are 1 and 5:
1 × 5 = 5
PRIME FACTORSAny whole number that is not prime (called a composite number) can be broken down into a product of prime factors.
For example, 12 can be broken down into prime factors:
The fundamental theorem of arithmetic states that all natural numbers are either prime numbers or a product of prime numbers.