You may never have heard of modular arithmetic, but you use it every day without the slightest difficulty. In this system, numbers wrap around when they reach a certain size called the modulus; it is ...

To multiply a negative number, an arithmetic binary shift moves all the digits in the binary number along to the left and fills the gaps after the shift with 0: to multiply by two, all digits shift ...

There are three kinds of prime numbers. The first is a solitary outlier: 2, the only even prime. After that, half the primes leave a remainder of 1 when divided by 4. The other half leave a remainder ...