678438 divided by 3 
We want to figure out the number of times 678438 can be divided by 3.

Step 1:
When dividing 6 by 3, we get 2 with a remainder of 0.
Write down 2 as next digit of the result. 
Result so far: 2.0
If we take 6 away from 6, we end up with 0.
Grab the next digit (7) from the dividend, add it to 0, then carry on: 7 / 3

Advancing to step 2:
When dividing 7 by 3, we get 2 with a remainder of 1.
Use 2 as the next digit of our solution. 
Result so far: 22.0
The remainder is 1 after subtracting 6 from 7.
Include the next digit (8) from the dividend after 1, then repeat: 18 / 3

Moving on to step 3:
When dividing 18 by 3, we get 6 with a remainder of 0.
The next digit of our result is 6. 
Result so far: 226.0
The remainder is 0 after subtracting 18 from 18.
Grab the next digit (4) from the dividend, add it to 0, then carry on: 4 / 3

Going ahead to step 4:
3 goes into 4 1 times with a remainder of 1.
Use 1 as the next digit of our solution. 
Result so far: 2261.0
Deduct 3 from 4 and we're left with 1.
Grab the next digit (3) from the dividend, add it to 1, then carry on: 13 / 3

Advancing to step 5:
The number 3 fits into 13 4 times, leaving a remainder of 1.
Write down 4 as next digit of the result. 
Result so far: 22614.0
If we take 12 away from 13, we end up with 1.
Bring next digit (8) of the dividend behind the 1 and repeat the process: 18 / 3

On to step 6:
When dividing 18 by 3, we get 6 with a remainder of 0.
The number 6 becomes the next digit in our result. 
Result so far: 226146.0
Deduct 18 from 18 and we're left with 0.
Since there are no more digits in the dividend, we add a zero to the remainder making it 0, and continue the process.

Step 7:
3 can be fit into 0 0 times, resulting in a remainder of 0.
Put 0 as the next digit of the answer. 
Result so far: 226146.0
The remainder is 0 after subtracting 0 from 0.
Since there are no more digits in the dividend, we add a zero to the remainder making it 0, and continue the process.

On to step 8:
The number 3 fits into 0 0 times, leaving a remainder of 0.
Put 0 as the next digit of the answer. 
Result so far: 226146.0
The remainder is 0 after subtracting 0 from 0.
Since there are no more digits in the dividend, we add a zero to the remainder making it 0, and continue the process.

The final outcome is 226146.0, with a leftover of 0.0.