Final answer:
The problem pertains to the sorting of numbers in descending order, starting from the largest to the smallest. This is a common method used in mathematics, particularly in statistics.
Step-by-step explanation:
The student's question pertains to the concept of ordering numbers from largest to smallest. The arrangement of numbers given in the question, 20.66, 12.61, 6.21, 2.62, 2.06, is a correct demonstration of a descending order, a method of sorting where numbers start from the highest and end at the lowest. It's important to understand this ordering method as it's commonly used in mathematics, particularly in statistics when you want to observe the value range in a data set, and for number comparison.
Learn more about Ordering Numbers