To represent "I think of a number, add 3 to it and multiply the result by 2" algebraically using $x$ as the unknown, the expression can be written as:

$2(x + 3)$

This is because you add 3 to the unknown number $x$, and then multiply the entire result by 2.

Do you want a detailed explanation of how this works or have any questions?

Here are five related questions to expand your understanding:

1. How would you write "Think of a number, subtract 5, and divide the result by 3" algebraically?
2. What is the difference between $2x + 3$ and $2(x + 3)$?
3. If $2(x + 3) = 14$, how would you solve for $x$?
4. How can algebraic expressions like this be used in solving word problems?
5. Can this algebraic expression be expanded? What does it become?

Tip: When dealing with word problems, focus on identifying keywords like "add," "subtract," "multiply," and "divide" to translate them into algebraic operations.