Learn about number patterns in arithmetic sequences with this BBC Bitesize Maths article. For students between the ages of 11 and 14. Finding the 𝒏th term of an arithmetic sequence Learn how to ...

Sometimes it’s informally called clock arithmetic, because it’s like how we tell the time: When we get around to 12 we start again at 1, so that 13 is “the same as” 1, 14 is “the same as ...

Unless you're in the military you'd say 2 o'clock, right? That's modular arithmetic, the modulus being 12. To add hours, we simply add them together: 9+5=14, and then subtract 12 to get 2.