6840 ÷ 3 = 2280 R0
Let's divide 6840 by 3.

Step 1:
3 goes into 6 2 times with a remainder of 0.
Write down 2 as next digit of of the result. 
Result so far: 2
Subtract 6 from 6 to get 0.
Bring next digit (8) of the dividend behind the 0 and repeat the process: 8 / 3

Step 2:
3 goes into 8 2 times with a remainder of 2.
Write down 2 as next digit of of the result. 
Result so far: 22
Subtract 6 from 8 to get 2.
Bring next digit (4) of the dividend behind the 2 and repeat the process: 24 / 3

Step 3:
3 goes into 24 8 times with a remainder of 0.
Write down 8 as next digit of of the result. 
Result so far: 228
Subtract 24 from 24 to get 0.
Bring next digit (0) of the dividend behind the 0 and repeat the process: 0 / 3

Step 4:
3 goes into 0 0 times with a remainder of 0.
Write down 0 as next digit of of the result. 
Result so far: 2280
Subtract 0 from 0 to get 0.

The final result is 2280 with a remainder of 0.