643743 divided by 3 
Let's see how many times 3 fits into 643743.

Step 1:
If we divide 6 by 3, we get 2 and a remainder of 0.
The next digit of our result is 2. 
Result so far: 2.0
Subtracting 6 from 6 leaves us with 0.
Append the next digit (4) from the dividend to 0 and continue with: 4 / 3

Step 2:
When dividing 4 by 3, we get 1 with a remainder of 1.
Use 1 as the next digit of our solution. 
Result so far: 21.0
The remainder is 1 after subtracting 3 from 4.
Append the next digit (3) from the dividend to 1 and continue with: 13 / 3

Advancing to step 3:
When dividing 13 by 3, we get 4 with a remainder of 1.
Put 4 as the next digit of the answer. 
Result so far: 214.0
If we subtract 12 from 13, we get 1.
Take the next digit (7) from the dividend and append it to 1, then repeat: 17 / 3

Advancing to step 4:
3 goes into 17 5 times with a remainder of 2.
Record the quotient 5 as the next digit in the result. 
Result so far: 2145.0
Subtract 15 from 17 to get 2.
Bring next digit (4) of the dividend behind the 2 and repeat the process: 24 / 3

Moving on to step 5:
The number 3 fits into 24 8 times, leaving a remainder of 0.
Write down 8 as next digit of the result. 
Result so far: 21458.0
Subtracting 24 from 24 leaves us with 0.
Bring next digit (3) of the dividend behind the 0 and repeat the process: 3 / 3

Advancing to step 6:
3 divided by 3 is 1 with a remainder of 0.
The number 1 becomes the next digit in our result. 
Result so far: 214581.0
Subtract 3 from 3 to get 0.
Since there are no more digits in the dividend, we add a zero to the remainder making it 0, and continue the process.

Going ahead to step 7:
3 goes into 0 0 times with a remainder of 0.
The number 0 becomes the next digit in our result. 
Result so far: 214581.0
Subtracting 0 from 0 leaves us 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.

Advancing to step 8:
When dividing 0 by 3, we get 0 with a remainder of 0.
Use 0 as the next digit of our solution. 
Result so far: 214581.0
Deduct 0 from 0 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.

The quotient of the division is 214581.0, and the remainder is 0.0.