7121 ÷ 1 = 7121 R0
No problem, we've got 7121 and 1 for the division.

Step 1:
1 goes into 7 7 times with a remainder of 0.
Write down 7 as next digit of of the result. 
Result so far: 7
Subtract 7 from 7 to get 0.
Bring next digit (1) of the dividend behind the 0 and repeat the process: 1 / 1

Step 2:
1 goes into 1 1 times with a remainder of 0.
Write down 1 as next digit of of the result. 
Result so far: 71
Subtract 1 from 1 to get 0.
Bring next digit (2) of the dividend behind the 0 and repeat the process: 2 / 1

Step 3:
1 goes into 2 2 times with a remainder of 0.
Write down 2 as next digit of of the result. 
Result so far: 712
Subtract 2 from 2 to get 0.
Bring next digit (1) of the dividend behind the 0 and repeat the process: 1 / 1

Step 4:
1 goes into 1 1 times with a remainder of 0.
Write down 1 as next digit of of the result. 
Result so far: 7121
Subtract 1 from 1 to get 0.

The final result is 7121 with a remainder of 0.