643867 ÷ 15 
Let's see how many times 15 fits into 643867.

On to step 1:
6 divided by 15 is 0 with a remainder of 6.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
Subtract 0 from 6 to get 6.
Take the next digit (4) from the dividend and append it to 6, then repeat: 64 / 15

On to step 2:
If we divide 64 by 15, we get 4 and a remainder of 4.
The number 4 becomes the next digit in our result. 
Result so far: 4.0
If we subtract 60 from 64, we get 4.
Bring next digit (3) of the dividend behind the 4 and repeat the process: 43 / 15

Advancing to step 3:
15 goes into 43 2 times with a remainder of 13.
The next digit of our result is 2. 
Result so far: 42.0
Subtracting 30 from 43 leaves us with 13.
Append the next digit (8) from the dividend to 13 and continue with: 138 / 15

Moving on to step 4:
15 can be fit into 138 9 times, resulting in a remainder of 3.
The next digit of our result is 9. 
Result so far: 429.0
Subtract 135 from 138 to get 3.
Fetch the next digit (6) from the dividend, attach it to 3 and continue: 36 / 15

On to step 5:
When dividing 36 by 15, we get 2 with a remainder of 6.
Record the quotient 2 as the next digit in the result. 
Result so far: 4292.0
If we take 30 away from 36, we end up with 6.
Grab the next digit (7) from the dividend, add it to 6, then carry on: 67 / 15

Advancing to step 6:
If we divide 67 by 15, we get 4 and a remainder of 7.
The next digit of our result is 4. 
Result so far: 42924.0
Subtracting 60 from 67 leaves us with 7.
Since there are no more digits in the dividend, we add a zero to the remainder making it 70, and continue the process.

Advancing to step 7:
When dividing 70 by 15, we get 4 with a remainder of 10.
Put 4 as the next digit of the answer. 
Result so far: 42924.4
Subtracting 60 from 70 leaves us with 10.
Since there are no more digits in the dividend, we add a zero to the remainder making it 100, and continue the process.

Advancing to step 8:
15 goes into 100 6 times with a remainder of 10.
Use 6 as the next digit of our solution. 
Result so far: 42924.46
Subtract 90 from 100 to get 10.
Since there are no more digits in the dividend, we add a zero to the remainder making it 100, and continue the process.

Step 9:
15 goes into 100 6 times with a remainder of 10.
The next digit of our result is 6. 
Result so far: 42924.466
Subtracting 90 from 100 leaves us with 10.
Since there are no more digits in the dividend, we add a zero to the remainder making it 100, and continue the process.

The quotient of the division is 42924.466, and the remainder is 0.001.