To solve 355 ÷ 7 using long division, follow these steps:

Step 1: Write the dividend (355) inside the long division symbol and the divisor (7) outside the symbol.

   7 │ 355

Step 2: Determine how many times the divisor (7) can be divided into the first digit of the dividend (3). In this case, 7 cannot be divided into 3, so we bring down the next digit (5) to create a new number.

   7 │ 355
       - 

Step 3: Divide the new number (35) by the divisor (7). The result is 5.

   7 │ 355
     - 35
       -
       5

Step 4: Multiply the divisor (7) by the quotient (5) and subtract the result from the new number (35). The result is 0.

   7 │ 355
     - 35
       -
       0

Step 5: Since the result is 0, there are no more digits to bring down. The quotient is the final result.

   7 │ 355
     - 35
       -
       0
     -----
       50

Therefore, 355 ÷ 7 = 50.