<Question>
Twelve friends met for dinner at Oscar's Overstuffed Oyster House, and each ordered one meal. The portions were so large, there was enough food for 18 people. If they share, how many meals should they have ordered to have just enough food for the 12 of them?
</Question>

<think>
<Plan_1>
Okay, let's try to figure out this problem. So, there are twelve friends who each ordered one meal, and the portions are so large that there's enough food for 18 people. Now, they want to share the food, and they need to know how many meals they should have ordered to have just enough for the 12 of them. Hmm, maybe I need to calculate how much food each person is actually consuming on average?

<prompt_1.1> Think about how to calculate the average amount of food each person consumes. </prompt_1.1>
</Plan_1>

<Execution_1>
<execution_1.1>
Let me start by understanding the problem again. Each of the twelve friends ordered one meal. But each meal is so big that if you take all twelve meals, there's enough to feed 18 people. Wait, that means the total amount of food ordered is enough for 18 people. But there are only 12 friends. So if they share, they need to figure out how many meals they actually need to order to have just enough for 12 people. Wait, but they already ordered 12 meals, which is enough for 18 people. So maybe they are asking, if they want to have just enough food for 12 people, how many meals should they have ordered instead of 12? Because if they order 12 meals, that's more than enough for 12 people. But maybe there's some waste or something, so they want to optimize the number of meals ordered.
</execution_1.1>
</Execution_1>

<Plan_2>
Based on execution_1.1:
Wait, but the problem says "the portions were so large, there was enough food for 18 people". So if each of the 12 friends ordered one meal, the total food is 12 portions, which is equivalent to 18 people. Therefore, each portion is 18/12 = 1.5 people portions?

<prompt_2.1> Calculate the average food consumption per person and determine the number of meals needed for 12 people. </prompt_2.1>

Wait, but that seems counterintuitive. If each meal is enough for 1.5 people, then 12 meals would be 12 * 1.5 = 18 people. So, if they want to have just enough for 12 people, how many meals should they order?

Alternatively, maybe we can think in terms of total food required. Let's say each person needs 1 unit of food.

<prompt_2.2> Use an alternative method to calculate the number of meals needed for 12 people. </prompt_2.2>
</Plan_2>

<Execution_2>
<execution_2.1>
Wait, maybe I need to think of it differently. If 12 meals are enough for 18 people, then each meal is equivalent to 18/12 = 1.5 person-meals. So each meal provides 1.5 servings, where a serving is for one person. Therefore, if they want to have enough for 12 people, they need 12 person-meals. Since each meal is 1.5 person-meals, the number of meals needed would be 12 / 1.5 = 8 meals.
</execution_2.1>

<execution_2.2>
Then 12 people would need 12 units. But the meals they ordered provide 18 units. So if they want to have just enough for 12 people, they need 12 units. Since each meal provides 1.5 units (because 12 meals = 18 units), then the number of meals needed would be 12 units divided by 1.5 units per meal. Let me calculate that: 12 / 1.5 = 8. So they should order 8 meals.
</execution_2.2>
</Execution_2>

<Plan_3>
Based on execution_2.1:
Let me check this again. If each meal is 1.5 person-meals, then 8 meals would be 8 * 1.5 = 12 person-meals.
Which is exactly what they need for 12 people. So, yes, they should have ordered 8 meals instead of 12. Therefore, the answer is 8.

Based on execution_2.2:
Wait, but maybe there's another way to think about it. If 12 meals serve 18 people, then the ratio of meals to people is 12:18, which simplifies to 2:3.

<prompt_3.1> Verify the solution using the ratio of meals to people. </prompt_3.1>

Based on execution_2.1, execution_2.2:
But let me make sure there's no trick here. The problem says "the portions were so large, there was enough food for 18 people".

<prompt_3.2> Ensure there's no trick in the problem statement and confirm the solution. </prompt_3.2>

Alternatively, maybe using proportions. If 12 meals = 18 people, then 1 meal = 1.5 people.

<prompt_3.3> Use proportions to calculate the number of meals needed for 12 people. </prompt_3.3>

But just to be thorough, let's consider another angle. Suppose each meal is a certain size. Let's say each person at dinner eats the same amount. Let's denote the amount each person eats as P. The total food ordered is 12 meals, each of size M. So total food is 12M. This is enough for 18 people, so each person's portion is P = 12M / 18 = (2/3)M. Therefore, each person is eating two-thirds of a meal. If there are 12 people, the total food needed is 12 * (2/3)M = 8M. So they need 8M amount of food. Since each meal is M, they need 8 meals. Therefore, the answer is 8.

I think that's solid. All different approaches lead to the same answer. So, the answer is 8.
</Plan_3>

<Execution_3>
<execution_3.1>
So, for 12 people, the number of meals needed would be (2/3)*12 = 8. Yes, that also gives 8. So both methods confirm that 8 meals are needed.
</execution_3.1>

<execution_3.2>
So each meal is equivalent to 1.5 people. Therefore, to serve 12 people, they need 12 / 1.5 = 8 meals. That makes sense. So instead of ordering 12 meals, which give 18 person-meals, they only need 8 meals to give 12 person-meals.
</execution_3.2>

<execution_3.3>
Therefore, to serve 12 people, each needing P, the number of meals needed is 12 / 1.5 = 8. Yep, same result. So regardless of the method, the answer is 8 meals.
</execution_3.3>
</Execution_3>

<Final_answer>
Therefore, the friends should have ordered $\boxed{8}$ meals to have just enough food for the 12 of them.
</Final_answer>
</think>