Juan says, " when you put togetherunequal groups, you can only add. " is he correct

Yes. If the groups were equal, you could multiply them to get the answer quicker. Since they are unequal, you can only add.

one direction rocks

No, Juan's statement is not correct. When you put together unequal groups, you can both add and subtract. Let me explain why:

Adding unequal groups:
When you add unequal groups, you are combining two or more groups that have different quantities. For example, if you have 3 apples and 4 oranges, you can add them together to have 3 apples + 4 oranges = 7 fruits. So, adding unequal groups is possible.

Subtracting unequal groups:
On the other hand, subtracting unequal groups is also possible. If you have 7 fruits (as in the previous example) and you want to find out how many oranges you have, you can subtract the number of apples from the total. In this case, subtracting the 3 apples from the 7 fruits would give you 7 fruits - 3 apples = 4 oranges.

In summary, when you put together unequal groups, you can both add and subtract, depending on the operation you want to perform.