你一定認識「1、2、3」這些數字，但你知道在英文裡要怎麼表達順序嗎？這種用來表示順序的數字，我們稱為「序數」，像是「First, Second, Third」。快來和同學們一起練習看看吧！跟著數一數，找找看這些同學的課室分別在幾樓呢？
You probably know the numbers "1, 2, 3," but do you know what ordinal numbers are? These are special numbers that help us count the order of things! For example, "1st, 2nd, 3rd." Let's practise with our student! Can you count along and find out what floor these students' classrooms are on?