12420 ÷ 7 = 1774 R2
No problem, we've got 12420 and 7 for the division.

Step 1:
7 goes into 1 0 times with a remainder of 1.
Write down 0 as next digit of of the result. 
Result so far: 0
Subtract 0 from 1 to get 1.
Bring next digit (2) of the dividend behind the 1 and repeat the process: 12 / 7

Step 2:
7 goes into 12 1 times with a remainder of 5.
Write down 1 as next digit of of the result. 
Result so far: 1
Subtract 7 from 12 to get 5.
Bring next digit (4) of the dividend behind the 5 and repeat the process: 54 / 7

Step 3:
7 goes into 54 7 times with a remainder of 5.
Write down 7 as next digit of of the result. 
Result so far: 17
Subtract 49 from 54 to get 5.
Bring next digit (2) of the dividend behind the 5 and repeat the process: 52 / 7

Step 4:
7 goes into 52 7 times with a remainder of 3.
Write down 7 as next digit of of the result. 
Result so far: 177
Subtract 49 from 52 to get 3.
Bring next digit (0) of the dividend behind the 3 and repeat the process: 30 / 7

Step 5:
7 goes into 30 4 times with a remainder of 2.
Write down 4 as next digit of of the result. 
Result so far: 1774
Subtract 28 from 30 to get 2.

The final result is 1774 with a remainder of 2.