### A Close Match

Can you massage the parameters of these curves to make them match as closely as possible?

### Prime Counter

A short challenge concerning prime numbers.

### The Right Volume

Can you rotate a curve to make a volume of 1?

# Sixinit

##### Age 16 to 18 ShortChallenge Level

Choose any whole number $n$, calculate $n^3 + 11n$, and divide by 6.

For what values of $n$ is your answer a whole number?
Can you explain why?

Did you know ... ?
Modular arithmetic is widely used to verify automatically whether a number has been correctly entered to a system. Each identification number (e.g. for passports, bank accounts, credit cards, ISBN book numbers and so on) obeys a rule which makes it easy to check (most of the time) whether or not the number has been copied correctly. For this reason such numbers are also called check codes.