# arithmetic

How would you explain the natural numbers to an alien devoid of a number instinct? You could try Peano arithmetic...

Explore the amazing patterns that reveal the powers hidden in the multiplication table!

There are triangular numbers hiding all over the standard multiplication table! Find out how to discover them in this article!

Are you bored with 1 to 12? Then have a look at these mathematical clock faces!

Need to find the least common multiple or greatest common divisor of two numbers? A billiard table of the right proportions holds the answers!

If you like playing with numbers, then this one's for you!

There are some amazing patterns hiding within simple arithmetic.

Some neat number tricks using numbers read backwards.

Eleven makes multiplication easy.

How to write down unimaginably large numbers using just a few symbols.

Why do we add fractions the way we do? A very close look at addition reveals the answer — and it also works for negative numbers.

The Indian way of adding fractions makes things easier (with musical explanation).

• Want facts and want them fast? Our Maths in a minute series explores key mathematical concepts in just a few words.