155^2

To calculate \( 155^2 \):

\[ 155^2 = 155 \times 155 \]

Calculating it step by step:

1. \( 155 \times 100 = 15500 \) (This is \( 155 \times 1 \) with two zeros added)
2. \( 155 \times 50 = 7750 \) (This is \( 155 \times 5 \) with one zero added)
3. \( 155 \times 5 = 775 \)

Now combine these products:

\[ 15500 + 7750 + 775 = 24025 \]

Thus,

\[ 155^2 = 24025 \]