We're dividing 53521857 by 643 
Let's see how many times 643 fits into 53521857.

Going ahead to step 1:
643 can be fit into 5 0 times, resulting in a remainder of 5.
Write down 0 as next digit of the result. 
Result so far: 0.0
The remainder is 5 after subtracting 0 from 5.
Append the next digit (3) from the dividend to 5 and continue with: 53 / 643

Moving on to step 2:
The number 643 fits into 53 0 times, leaving a remainder of 53.
Put 0 as the next digit of the answer. 
Result so far: 0.0
If we subtract 0 from 53, we get 53.
Bring next digit (5) of the dividend behind the 53 and repeat the process: 535 / 643

Step 3:
If we divide 535 by 643, we get 0 and a remainder of 535.
The next digit of our result is 0. 
Result so far: 0.0
Deduct 0 from 535 and we're left with 535.
Bring next digit (2) of the dividend behind the 535 and repeat the process: 5352 / 643

Moving on to step 4:
5352 divided by 643 is 8 with a remainder of 208.
Put 8 as the next digit of the answer. 
Result so far: 8.0
Subtract 5144 from 5352 to get 208.
Include the next digit (1) from the dividend after 208, then repeat: 2081 / 643

Let's proceed to step 5:
643 can be fit into 2081 3 times, resulting in a remainder of 152.
Put 3 as the next digit of the answer. 
Result so far: 83.0
If we subtract 1929 from 2081, we get 152.
Bring next digit (8) of the dividend behind the 152 and repeat the process: 1528 / 643

Step 6:
The number 643 fits into 1528 2 times, leaving a remainder of 242.
Put 2 as the next digit of the answer. 
Result so far: 832.0
Deduct 1286 from 1528 and we're left with 242.
Include the next digit (5) from the dividend after 242, then repeat: 2425 / 643

Advancing to step 7:
When dividing 2425 by 643, we get 3 with a remainder of 496.
Write down 3 as next digit of the result. 
Result so far: 8323.0
Subtract 1929 from 2425 to get 496.
Take the next digit (7) from the dividend and append it to 496, then repeat: 4967 / 643

On to step 8:
643 can be fit into 4967 7 times, resulting in a remainder of 466.
The number 7 becomes the next digit in our result. 
Result so far: 83237.0
Subtract 4501 from 4967 to get 466.
Since there are no more digits in the dividend, we add a zero to the remainder making it 4660, and continue the process.

Moving on to step 9:
If we divide 4660 by 643, we get 7 and a remainder of 159.
Use 7 as the next digit of our solution. 
Result so far: 83237.7
If we subtract 4501 from 4660, we get 159.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1590, and continue the process.

Going ahead to step 10:
If we divide 1590 by 643, we get 2 and a remainder of 304.
Use 2 as the next digit of our solution. 
Result so far: 83237.72
Deduct 1286 from 1590 and we're left with 304.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3040, and continue the process.

Step 11:
If we divide 3040 by 643, we get 4 and a remainder of 468.
The number 4 becomes the next digit in our result. 
Result so far: 83237.724
If we subtract 2572 from 3040, we get 468.
Since there are no more digits in the dividend, we add a zero to the remainder making it 4680, and continue the process.

On to step 12:
4680 divided by 643 is 7 with a remainder of 179.
Record the quotient 7 as the next digit in the result. 
Result so far: 83237.7247
The remainder is 179 after subtracting 4501 from 4680.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1790, and continue the process.

Going ahead to step 13:
643 goes into 1790 2 times with a remainder of 504.
Record the quotient 2 as the next digit in the result. 
Result so far: 83237.72472
If we take 1286 away from 1790, we end up with 504.
Since there are no more digits in the dividend, we add a zero to the remainder making it 5040, and continue the process.

Moving on to step 14:
643 goes into 5040 7 times with a remainder of 539.
Put 7 as the next digit of the answer. 
Result so far: 83237.724727
Deduct 4501 from 5040 and we're left with 539.
Since there are no more digits in the dividend, we add a zero to the remainder making it 5390, and continue the process.

Moving on to step 15:
5390 divided by 643 is 8 with a remainder of 246.
Record the quotient 8 as the next digit in the result. 
Result so far: 83237.7247278
If we take 5144 away from 5390, we end up with 246.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2460, and continue the process.

Let's proceed to step 16:
If we divide 2460 by 643, we get 3 and a remainder of 531.
The number 3 becomes the next digit in our result. 
Result so far: 83237.72472783
The remainder is 531 after subtracting 1929 from 2460.
Since there are no more digits in the dividend, we add a zero to the remainder making it 5310, and continue the process.

After the division, we end up with 83237.72472783 and a remainder of 5.31e-07.