351785 divided by 21 
We want to figure out the number of times 351785 can be divided by 21.

Step 1:
3 divided by 21 is 0 with a remainder of 3.
The next digit of our result is 0. 
Result so far: 0.0
If we subtract 0 from 3, we get 3.
Fetch the next digit (5) from the dividend, attach it to 3 and continue: 35 / 21

Step 2:
21 can be fit into 35 1 times, resulting in a remainder of 14.
The next digit of our result is 1. 
Result so far: 1.0
Deduct 21 from 35 and we're left with 14.
Append the next digit (1) from the dividend to 14 and continue with: 141 / 21

Let's proceed to step 3:
21 can be fit into 141 6 times, resulting in a remainder of 15.
The next digit of our result is 6. 
Result so far: 16.0
The remainder is 15 after subtracting 126 from 141.
Bring next digit (7) of the dividend behind the 15 and repeat the process: 157 / 21

Going ahead to step 4:
When dividing 157 by 21, we get 7 with a remainder of 10.
Use 7 as the next digit of our solution. 
Result so far: 167.0
Subtracting 147 from 157 leaves us with 10.
Bring next digit (8) of the dividend behind the 10 and repeat the process: 108 / 21

Let's proceed to step 5:
21 can be fit into 108 5 times, resulting in a remainder of 3.
Use 5 as the next digit of our solution. 
Result so far: 1675.0
The remainder is 3 after subtracting 105 from 108.
Fetch the next digit (5) from the dividend, attach it to 3 and continue: 35 / 21

Step 6:
21 goes into 35 1 times with a remainder of 14.
Put 1 as the next digit of the answer. 
Result so far: 16751.0
Subtracting 21 from 35 leaves us with 14.
Since there are no more digits in the dividend, we add a zero to the remainder making it 140, and continue the process.

Let's proceed to step 7:
21 can be fit into 140 6 times, resulting in a remainder of 14.
The next digit of our result is 6. 
Result so far: 16751.6
Subtract 126 from 140 to get 14.
Since there are no more digits in the dividend, we add a zero to the remainder making it 140, and continue the process.

On to step 8:
140 divided by 21 is 6 with a remainder of 14.
Record the quotient 6 as the next digit in the result. 
Result so far: 16751.66
Subtracting 126 from 140 leaves us with 14.
Since there are no more digits in the dividend, we add a zero to the remainder making it 140, and continue the process.

The final result is 16751.66 with a remainder of 0.014.