The expression "three less than the product of two and a number $y$" can be translated into a mathematical expression as follows:

$2y - 3$

This represents the product of 2 and $y$ (which is $2y$), and then subtracting 3.

Would you like more details or have any questions about this expression?

Here are five related questions to consider:

1. How would you express "five more than twice a number $y$"?
2. What would the expression look like for "seven less than the square of a number $y$"?
3. How can you represent "three times a number $y$, decreased by four"?
4. How do you express "the sum of twice a number $y$ and ten"?
5. How would you write "half of a number $y$ minus two"?

Tip: When translating phrases into algebraic expressions, identify the operations (addition, subtraction, multiplication, etc.) and the quantities involved, then assemble the expression step by step.