Dance stands for the number 5, because the homonym of dance in this question is five, and the homonym of five is five. In other words, there are five idioms about dancing, that is, Xiang Zhuang dances with swords, singing and dancing, flying while dancing, singing and dancing with joy.

Twenty-one plus five, three transgressions of five divided by two, bumper crops, all corners of the country, three orders and five applications, three transgressions of five times, colorful, colorful and so on. To sum up, dance represents the number five.