**9.9** is larger than 9.11.

Here's a simple way to see it:

1.  **Line up the decimals:**
    9.11
    9.9

2.  **Compare the whole numbers:** Both have a 9, so they are equal so far.

3.  **Compare the first digit after the decimal (the tenths place):**
    *   9.11 has a **1** in the tenths place.
    *   9.9 has a **9** in the tenths place.

Since 9 is larger than 1, **9.9 is the larger number**.

You can also think of it like this: 9.9 is the same as 9.90. It's much easier to see that 9.90 is larger than 9.11.
