To write an expression that represents Max's number based on the instructions, let's break down the steps:

1. Max has a number $n$.
2. He adds 8 to this number, which gives $n + 8$.
3. He then doubles the sum, meaning we multiply this result by 2.

So, the expression to represent Max's number is:

$2 \times (n + 8)$

Or, equivalently:

$2(n + 8)$

This expression captures the operations described in the problem.

Would you like further details or have any questions?

Here are some related questions for further practice:

1. What would the expression look like if Max tripled the sum instead of doubling it?
2. How would the expression change if Max subtracted 8 instead of adding it, before doubling?
3. If Max had added 10 instead of 8, what would the expression be?
4. What is the result if $n = 5$ in the expression $2(n + 8)$?
5. How would you express the process if Max first doubled $n$ and then added 8?

Tip: Remember to always perform operations inside parentheses first when they are present in an expression.