What was the purpose of the Eratosthenes sieve?
to check whether a given number is divisible by 7
to round numbers to 10 decimal places
for determining consecutive digits in the number π.
for finding all prime numbers up to any given limit
In mathematics, the sieve of Eratosthenes is a simple, ancient algorithm for finding all prime numbers up to any given limit. It does so by iteratively marking as composite (i.e., not prime) the multiples of each prime, starting with the first prime number, 2.