Natural numbers are those numbers that you’re using every day. Natural numbers are including values from 1 to infinity.
All the numbers you may count on your fingers and toes are natural numbers.
Next Lesson: Prime Numbers and Factoring
Transcript of the video.
Natural Numbers. Examples are: 1, 2, 5, 18, 150, 1,586, 258, 569.
We refer to whole numbers when we mean natural numbers except that whole numbers also include 0.
Did you see how these number lines all start at 0? Number lines that have integers may have every positive or negative number.
Rational numbers are just other terms for fractions. The word “rational” is derived from the word “ratio”. When we refer to a rational number, we talk about a ratio of two integers.
Prime and Composite Numbers
Chances are you have heard of “Prime Numbers”. A Prime Number is special because it can only be evenly divided by 1 and itself. Numbers like six, for example, may be divided by 1, 2, 3, and 6. When you are dividing by these numbers, there is no remainder. A prime number, for example, 7, can be divided by only by 1 and 7 with no remainder.
• Can negative numbers be prime numbers? No. Negative numbers don’t symbolize natural numbers. That means there are no fractions as well.
• Can zero be among prime numbers? No. To make a prime number, you need to have two divisors. Whereas zero may be divided by actually any number, you are not able to divide by zero.
• Is “1” a prime number? Well, No. You will need, again, two divisors to be able to make a prime number (one and itself). In a technical way, “1” has only one divisor so it is not a prime number.
The opposite of prime numbers are composite numbers. We talked before about how we can divide six 1, 6, 2, and 3. So we talk about six as a composite number as it can be divided by many different numbers without having a remainder left.