4415983 ÷ 21 
We're looking to find how many times 21 goes into 4415983.

Advancing to step 1:
21 can be fit into 4 0 times, resulting in a remainder of 4.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
If we take 0 away from 4, we end up with 4.
Grab the next digit (4) from the dividend, add it to 4, then carry on: 44 / 21

Step 2:
The number 21 fits into 44 2 times, leaving a remainder of 2.
Use 2 as the next digit of our solution. 
Result so far: 2.0
Subtracting 42 from 44 leaves us with 2.
Take the next digit (1) from the dividend and append it to 2, then repeat: 21 / 21

Advancing to step 3:
If we divide 21 by 21, we get 1 and a remainder of 0.
Put 1 as the next digit of the answer. 
Result so far: 21.0
Deduct 21 from 21 and we're left with 0.
Fetch the next digit (5) from the dividend, attach it to 0 and continue: 5 / 21

Going ahead to step 4:
5 divided by 21 is 0 with a remainder of 5.
The number 0 becomes the next digit in our result. 
Result so far: 210.0
Deduct 0 from 5 and we're left with 5.
Fetch the next digit (9) from the dividend, attach it to 5 and continue: 59 / 21

Let's proceed to step 5:
When dividing 59 by 21, we get 2 with a remainder of 17.
Record the quotient 2 as the next digit in the result. 
Result so far: 2102.0
Subtracting 42 from 59 leaves us with 17.
Append the next digit (8) from the dividend to 17 and continue with: 178 / 21

Going ahead to step 6:
21 can be fit into 178 8 times, resulting in a remainder of 10.
Record the quotient 8 as the next digit in the result. 
Result so far: 21028.0
If we take 168 away from 178, we end up with 10.
Bring next digit (3) of the dividend behind the 10 and repeat the process: 103 / 21

Going ahead to step 7:
21 goes into 103 4 times with a remainder of 19.
Record the quotient 4 as the next digit in the result. 
Result so far: 210284.0
Subtracting 84 from 103 leaves us with 19.
Since there are no more digits in the dividend, we add a zero to the remainder making it 190, and continue the process.

Advancing to step 8:
21 can be fit into 190 9 times, resulting in a remainder of 1.
Record the quotient 9 as the next digit in the result. 
Result so far: 210284.9
Subtract 189 from 190 to get 1.
Since there are no more digits in the dividend, we add a zero to the remainder making it 10, and continue the process.

Moving on to step 9:
21 can be fit into 10 0 times, resulting in a remainder of 10.
Record the quotient 0 as the next digit in the result. 
Result so far: 210284.9
Subtract 0 from 10 to get 10.
Since there are no more digits in the dividend, we add a zero to the remainder making it 100, and continue the process.

Step 10:
The number 21 fits into 100 4 times, leaving a remainder of 16.
Record the quotient 4 as the next digit in the result. 
Result so far: 210284.904
Subtract 84 from 100 to get 16.
Since there are no more digits in the dividend, we add a zero to the remainder making it 160, and continue the process.

On to step 11:
21 goes into 160 7 times with a remainder of 13.
Record the quotient 7 as the next digit in the result. 
Result so far: 210284.9047
If we subtract 147 from 160, we get 13.
Since there are no more digits in the dividend, we add a zero to the remainder making it 130, and continue the process.

Going ahead to step 12:
The number 21 fits into 130 6 times, leaving a remainder of 4.
The next digit of our result is 6. 
Result so far: 210284.90476
The remainder is 4 after subtracting 126 from 130.
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:
21 can be fit into 40 1 times, resulting in a remainder of 19.
The number 1 becomes the next digit in our result. 
Result so far: 210284.904761
Deduct 21 from 40 and we're left with 19.
Since there are no more digits in the dividend, we add a zero to the remainder making it 190, and continue the process.

Advancing to step 14:
When dividing 190 by 21, we get 9 with a remainder of 1.
Write down 9 as next digit of the result. 
Result so far: 210284.9047619
Subtracting 189 from 190 leaves us 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.

Let's proceed to step 15:
If we divide 10 by 21, we get 0 and a remainder of 10.
Use 0 as the next digit of our solution. 
Result so far: 210284.9047619
Deduct 0 from 10 and we're left with 10.
Since there are no more digits in the dividend, we add a zero to the remainder making it 100, and continue the process.

The final outcome is 210284.9047619, with a leftover of 1e-08.