Number + 堂 + Class Noun
堂 (táng) is a measure word used to count class sessions or lessons. It is placed between a number and the type of class, as in 一堂课 (yī táng kè, "one class session"). It emphasizes the formal, structured nature of the lesson.
今天下午有两堂数学课。
Jīntiān xiàwǔ yǒu liǎng táng shùxué kè.
There are two math classes this afternoon.
这堂课的内容特别有意思。
Zhè táng kè de nèiróng tèbié yǒu yìsi.
The content of this class is especially interesting.
老师每堂课都会提问好几个学生。
Lǎoshī měi táng kè dōu huì tíwèn hǎo jǐ ge xuéshēng.
The teacher calls on several students in every class.