7781 ÷ 7 = 1111 R4
We're going to perform division on 7781 with 7 as the divisor.

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

Step 2:
7 goes into 7 1 times with a remainder of 0.
Write down 1 as next digit of of the result. 
Result so far: 11
Subtract 7 from 7 to get 0.
Bring next digit (8) of the dividend behind the 0 and repeat the process: 8 / 7

Step 3:
7 goes into 8 1 times with a remainder of 1.
Write down 1 as next digit of of the result. 
Result so far: 111
Subtract 7 from 8 to get 1.
Bring next digit (1) of the dividend behind the 1 and repeat the process: 11 / 7

Step 4:
7 goes into 11 1 times with a remainder of 4.
Write down 1 as next digit of of the result. 
Result so far: 1111
Subtract 7 from 11 to get 4.

The final result is 1111 with a remainder of 4.