There are 46 prime numbers between 1 and 200. There are 25 prime numbers between 1 and 100.

Twin-Primes: A pair of prime numbers are known as twin primes if there is only one composite number between them. So, (3, 5), (11, 19) are some examples of co-primes. This is because, out of their two factors, the common factor can only be 1. Note that pairs of any 2 prime numbers are always co-primes. It is not necessary for these numbers to be prime numbers. Terms Related to Prime NumbersĬo-Primes: Two numbers are said to be co-prime if they have only one common factor, that is, 1. Step 5: Continue the process of encircling the next uncrossed number and crossing out its multiples till all the numbers in the table are either encircled or crossed out, except 1. Ignore the previously crossed-out numbers like 6, 12, 18, and so on.

Step 4: Encircle the next uncrossed number, which is 3, and cross out all its multiples. Step 3: Encircle 2 and cross out all its multiples as they are not prime. Step 2: Leave 1 as it is neither a prime number nor a composite number. In the third century BCE, the Greek mathematician Eratosthenes found a very simple method of finding prime numbers.įollow the given steps to identify the prime numbers between 1 and 100.

Multiplication chart 1 to 100 printable