The product rule is like mixing two things together to get a new thing! When you have two things that are different, but you want to find out how they work together, you can use the product rule.
Let's say you have two numbers, like 3 and 5. When you want to multiply them together, you use the product rule. You would take the first number, 3, and multiply it by the second number, 5. Then you would get a new number, 15, which is the product of the two numbers.
But what if you have two things that aren't just numbers? Like maybe you have a big box of toys and a small box of candy. You might want to find out how many different toy-candy combinations you can make with them. This is where the product rule comes in handy.
To use the product rule with non-number things, you just need to make sure that you're keeping them separate. So you would count how many toys you have, and how many pieces of candy you have, and then multiply those numbers together. This gives you the total number of toy-candy combinations there are!
The product rule works with lots of different things. You can use it with letters, animals, shapes, or anything else that you want to mix together. As long as you're keeping them separate and then multiplying them together, you're using the product rule!