Final answer:
To arrange from greatest to least, compare digits starting from the highest place value. Here, the order is 9.55, 9.45, 9.16, 8.91, and 1.99.
Step-by-step explanation:
The order of the given numbers from greatest to least is as follows: 9.55, 9.45, 9.16, 8.91, and 1.99. When comparing these numbers, we focus on the highest place value first, which is the units place. Since 9 is the greatest digit in the units place among these numbers, we first compare numbers starting with 9.
The highest number among those starting with 9 is 9.55, followed by 9.45, 9.16, and then 8.91 has the next greatest value owing to the digit 8 in the units place. Finally, 1.99 is the least among the given numbers because it has the smallest units digit. By listing the numbers in this sequence, we have correctly ordered them from greatest to least.