Answer :

To arrange the numbers 1.1, 0.01, and 0.001 in descending order (from biggest to smallest), follow these steps:

1. Identify the Numbers:
- We have three numbers: 1.1, 0.01, and 0.001.

2. Compare the Numbers:
- Begin by comparing the numbers to determine their order.
- First, compare 1.1 and 0.01. Since 1.1 is greater than 0.01, 1.1 is the largest so far.
- Next, compare 1.1 with 0.001. Since 1.1 is greater than 0.001, 1.1 remains the largest.
- Then, compare 0.01 with 0.001. Since 0.01 is greater than 0.001, 0.01 is positioned before 0.001.

3. Arrange the Numbers:
- After comparing the numbers, we see that 1.1 is the largest, followed by 0.01, and then 0.001.

4. Write the Numbers in Descending Order:
- The arrangement in descending order (from biggest to smallest) is: 1.1, 0.01, and 0.001.

Hence, the numbers 1.1, 0.01, and 0.001 arranged in descending order are:
[tex]\[ 1.1, 0.01, 0.001 \][/tex]