Solve Vertical Addition: 999 + 185 Step-by-Step

To solve this problem, we'll perform vertical addition. Here are the steps:

• Step 1: Write the numbers 999 and 185 vertically, aligning them by the rightmost digit.
• Step 2: Begin adding from the rightmost column.

Let's start with the units column:

• The unit digits are 9 (from 999) and 5 (from 185).
• Add them: $9 + 5 = 14$.
• Write down 4 and carry over 1 to the next column (tens place).

Next, the tens column:

• The tens digits are 9 (from 999) and 8 (from 185), plus the carry-over value 1.
• Add them: $9 + 8 + 1 = 18$.
• Write down 8 and carry over 1 to the next column (hundreds place).

Finally, the hundreds column:

• The hundreds digits are 9 (from 999) and 1 (from 185), plus the carry-over value 1.
• Add them: $9 + 1 + 1 = 11$.
• Write down 1 and carry over the 1 to form a new thousands column.

Since there's nothing else to add in the thousands column, write down the carry-over as 1.

Therefore, the sum of 999 and 185 is $\mathbf{1184}$.