Learn Icelandic: Þetta eru tveir miðar, ekki þrír.

In Icelandic, the numbers 1, 2, 3, and 4 change to match the gender of the noun they are counting. The word for ticket, miði, is masculine. Since we have more than one, it becomes miðar, and we must use the masculine form of the number two, which is tveir.

Why is the word for three, þrír, masculine even though there is no noun after it?

Even though the word miðar isn't repeated at the end of the sentence, we are still talking about tickets. The number must still match the masculine gender of the hidden noun, so we use the masculine form þrír.

If miðar is plural, why does the sentence start with the singular word Þetta instead of a plural word for "these"?

When introducing or pointing to something with "This is" or "These are", Icelandic always uses the fixed neuter singular word Þetta. You just change the verb to match the number of things. So "This is" is Þetta er, and "These are" is Þetta eru.

How can I remember that miðar is a masculine noun?

Miðar is the plural form of miði (ticket). A handy trick for beginners: if a noun ends in -i in its singular dictionary form, it is almost always masculine. These nouns typically drop the -i and add -ar to become plural.