We divide 643390 by 61
We're looking to find how many times 61 goes into 643390.

Step 1:
61 goes into 6 0 times with a remainder of 6.
The next digit of our result is 0. 
Result so far: 0.0
Subtracting 0 from 6 leaves us with 6.
Grab the next digit (4) from the dividend, add it to 6, then carry on: 64 / 61

Let's proceed to step 2:
61 can be fit into 64 1 times, resulting in a remainder of 3.
Use 1 as the next digit of our solution. 
Result so far: 1.0
The remainder is 3 after subtracting 61 from 64.
Bring next digit (3) of the dividend behind the 3 and repeat the process: 33 / 61

Going ahead to step 3:
61 can be fit into 33 0 times, resulting in a remainder of 33.
The next digit of our result is 0. 
Result so far: 10.0
Subtract 0 from 33 to get 33.
Bring next digit (3) of the dividend behind the 33 and repeat the process: 333 / 61

Moving on to step 4:
When dividing 333 by 61, we get 5 with a remainder of 28.
Put 5 as the next digit of the answer. 
Result so far: 105.0
The remainder is 28 after subtracting 305 from 333.
Append the next digit (9) from the dividend to 28 and continue with: 289 / 61

Let's proceed to step 5:
When dividing 289 by 61, we get 4 with a remainder of 45.
The next digit of our result is 4. 
Result so far: 1054.0
If we subtract 244 from 289, we get 45.
Append the next digit (0) from the dividend to 45 and continue with: 450 / 61

Going ahead to step 6:
61 goes into 450 7 times with a remainder of 23.
Write down 7 as next digit of the result. 
Result so far: 10547.0
If we subtract 427 from 450, we get 23.
Since there are no more digits in the dividend, we add a zero to the remainder making it 230, and continue the process.

Moving on to step 7:
The number 61 fits into 230 3 times, leaving a remainder of 47.
Record the quotient 3 as the next digit in the result. 
Result so far: 10547.3
If we subtract 183 from 230, we get 47.
Since there are no more digits in the dividend, we add a zero to the remainder making it 470, and continue the process.

Moving on to step 8:
If we divide 470 by 61, we get 7 and a remainder of 43.
Write down 7 as next digit of the result. 
Result so far: 10547.37
If we subtract 427 from 470, we get 43.
Since there are no more digits in the dividend, we add a zero to the remainder making it 430, and continue the process.

Moving on to step 9:
430 divided by 61 is 7 with a remainder of 3.
The number 7 becomes the next digit in our result. 
Result so far: 10547.377
If we take 427 away from 430, we end up with 3.
Since there are no more digits in the dividend, we add a zero to the remainder making it 30, and continue the process.

After the division, we end up with 10547.377 and a remainder of 0.0003.