We divide 643599 by 30
Let's see how many times 30 fits into 643599.

Moving on to step 1:
30 goes into 6 0 times with a remainder of 6.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
Subtracting 0 from 6 leaves us with 6.
Bring next digit (4) of the dividend behind the 6 and repeat the process: 64 / 30

Moving on to step 2:
If we divide 64 by 30, we get 2 and a remainder of 4.
The number 2 becomes the next digit in our result. 
Result so far: 2.0
If we take 60 away from 64, we end up with 4.
Bring next digit (3) of the dividend behind the 4 and repeat the process: 43 / 30

Step 3:
The number 30 fits into 43 1 times, leaving a remainder of 13.
Put 1 as the next digit of the answer. 
Result so far: 21.0
If we take 30 away from 43, we end up with 13.
Grab the next digit (5) from the dividend, add it to 13, then carry on: 135 / 30

Moving on to step 4:
When dividing 135 by 30, we get 4 with a remainder of 15.
Record the quotient 4 as the next digit in the result. 
Result so far: 214.0
Subtracting 120 from 135 leaves us with 15.
Take the next digit (9) from the dividend and append it to 15, then repeat: 159 / 30

Step 5:
30 goes into 159 5 times with a remainder of 9.
The number 5 becomes the next digit in our result. 
Result so far: 2145.0
If we take 150 away from 159, we end up with 9.
Include the next digit (9) from the dividend after 9, then repeat: 99 / 30

Let's proceed to step 6:
If we divide 99 by 30, we get 3 and a remainder of 9.
Put 3 as the next digit of the answer. 
Result so far: 21453.0
Deduct 90 from 99 and we're left with 9.
Since there are no more digits in the dividend, we add a zero to the remainder making it 90, and continue the process.

On to step 7:
If we divide 90 by 30, we get 3 and a remainder of 0.
The next digit of our result is 3. 
Result so far: 21453.3
Subtract 90 from 90 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.

Moving on to step 8:
30 can be fit into 0 0 times, resulting in a remainder of 0.
Use 0 as the next digit of our solution. 
Result so far: 21453.3
Subtract 0 from 0 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.

Step 9:
When dividing 0 by 30, we get 0 with a remainder of 0.
Put 0 as the next digit of the answer. 
Result so far: 21453.3
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.

Our division results in 21453.3 with a remaining 0.0.