We look at the division of 398521 by 7 
Let's see how many times 7 fits into 398521.

Moving on to step 1:
When dividing 3 by 7, we get 0 with a remainder of 3.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
If we take 0 away from 3, we end up with 3.
Fetch the next digit (9) from the dividend, attach it to 3 and continue: 39 / 7

Moving on to step 2:
When dividing 39 by 7, we get 5 with a remainder of 4.
Use 5 as the next digit of our solution. 
Result so far: 5.0
Subtracting 35 from 39 leaves us with 4.
Append the next digit (8) from the dividend to 4 and continue with: 48 / 7

Step 3:
7 can be fit into 48 6 times, resulting in a remainder of 6.
Write down 6 as next digit of the result. 
Result so far: 56.0
Deduct 42 from 48 and we're left with 6.
Bring next digit (5) of the dividend behind the 6 and repeat the process: 65 / 7

Advancing to step 4:
65 divided by 7 is 9 with a remainder of 2.
The number 9 becomes the next digit in our result. 
Result so far: 569.0
Subtract 63 from 65 to get 2.
Grab the next digit (2) from the dividend, add it to 2, then carry on: 22 / 7

Moving on to step 5:
7 goes into 22 3 times with a remainder of 1.
Write down 3 as next digit of the result. 
Result so far: 5693.0
If we take 21 away from 22, we end up with 1.
Include the next digit (1) from the dividend after 1, then repeat: 11 / 7

Let's proceed to step 6:
If we divide 11 by 7, we get 1 and a remainder of 4.
Write down 1 as next digit of the result. 
Result so far: 56931.0
If we subtract 7 from 11, we get 4.
Since there are no more digits in the dividend, we add a zero to the remainder making it 40, and continue the process.

Step 7:
7 can be fit into 40 5 times, resulting in a remainder of 5.
The next digit of our result is 5. 
Result so far: 56931.5
The remainder is 5 after subtracting 35 from 40.
Since there are no more digits in the dividend, we add a zero to the remainder making it 50, and continue the process.

Let's proceed to step 8:
When dividing 50 by 7, we get 7 with a remainder of 1.
Put 7 as the next digit of the answer. 
Result so far: 56931.57
If we take 49 away from 50, we end up with 1.
Since there are no more digits in the dividend, we add a zero to the remainder making it 10, and continue the process.

Going ahead to step 9:
The number 7 fits into 10 1 times, leaving a remainder of 3.
The number 1 becomes the next digit in our result. 
Result so far: 56931.571
If we subtract 7 from 10, we get 3.
Since there are no more digits in the dividend, we add a zero to the remainder making it 30, and continue the process.

Let's proceed to step 10:
If we divide 30 by 7, we get 4 and a remainder of 2.
Put 4 as the next digit of the answer. 
Result so far: 56931.5714
Subtract 28 from 30 to get 2.
Since there are no more digits in the dividend, we add a zero to the remainder making it 20, and continue the process.

Moving on to step 11:
If we divide 20 by 7, we get 2 and a remainder of 6.
Record the quotient 2 as the next digit in the result. 
Result so far: 56931.57142
If we take 14 away from 20, we end up with 6.
Since there are no more digits in the dividend, we add a zero to the remainder making it 60, and continue the process.

On to step 12:
The number 7 fits into 60 8 times, leaving a remainder of 4.
Put 8 as the next digit of the answer. 
Result so far: 56931.571428
The remainder is 4 after subtracting 56 from 60.
Since there are no more digits in the dividend, we add a zero to the remainder making it 40, and continue the process.

On to step 13:
If we divide 40 by 7, we get 5 and a remainder of 5.
Record the quotient 5 as the next digit in the result. 
Result so far: 56931.5714285
If we subtract 35 from 40, we get 5.
Since there are no more digits in the dividend, we add a zero to the remainder making it 50, and continue the process.

Let's proceed to step 14:
7 can be fit into 50 7 times, resulting in a remainder of 1.
Put 7 as the next digit of the answer. 
Result so far: 56931.57142857
If we take 49 away from 50, we end up with 1.
Since there are no more digits in the dividend, we add a zero to the remainder making it 10, and continue the process.

After the division, we end up with 56931.57142857 and a remainder of 1e-09.