79668483 ÷ 21 
We're looking to find how many times 21 goes into 79668483.

Advancing to step 1:
When dividing 7 by 21, we get 0 with a remainder of 7.
Put 0 as the next digit of the answer. 
Result so far: 0.0
Subtracting 0 from 7 leaves us with 7.
Include the next digit (9) from the dividend after 7, then repeat: 79 / 21

Advancing to step 2:
79 divided by 21 is 3 with a remainder of 16.
The next digit of our result is 3. 
Result so far: 3.0
Deduct 63 from 79 and we're left with 16.
Include the next digit (6) from the dividend after 16, then repeat: 166 / 21

On to step 3:
21 can be fit into 166 7 times, resulting in a remainder of 19.
Use 7 as the next digit of our solution. 
Result so far: 37.0
Subtracting 147 from 166 leaves us with 19.
Include the next digit (6) from the dividend after 19, then repeat: 196 / 21

Moving on to step 4:
If we divide 196 by 21, we get 9 and a remainder of 7.
The number 9 becomes the next digit in our result. 
Result so far: 379.0
If we subtract 189 from 196, we get 7.
Fetch the next digit (8) from the dividend, attach it to 7 and continue: 78 / 21

Moving on to step 5:
When dividing 78 by 21, we get 3 with a remainder of 15.
Write down 3 as next digit of the result. 
Result so far: 3793.0
If we subtract 63 from 78, we get 15.
Bring next digit (4) of the dividend behind the 15 and repeat the process: 154 / 21

On to step 6:
When dividing 154 by 21, we get 7 with a remainder of 7.
Use 7 as the next digit of our solution. 
Result so far: 37937.0
Subtract 147 from 154 to get 7.
Bring next digit (8) of the dividend behind the 7 and repeat the process: 78 / 21

On to step 7:
78 divided by 21 is 3 with a remainder of 15.
Put 3 as the next digit of the answer. 
Result so far: 379373.0
Subtracting 63 from 78 leaves us with 15.
Fetch the next digit (3) from the dividend, attach it to 15 and continue: 153 / 21

Let's proceed to step 8:
153 divided by 21 is 7 with a remainder of 6.
The next digit of our result is 7. 
Result so far: 3793737.0
If we subtract 147 from 153, we get 6.
Since there are no more digits in the dividend, we add a zero to the remainder making it 60, and continue the process.

Advancing to step 9:
If we divide 60 by 21, we get 2 and a remainder of 18.
Record the quotient 2 as the next digit in the result. 
Result so far: 3793737.2
Subtracting 42 from 60 leaves us with 18.
Since there are no more digits in the dividend, we add a zero to the remainder making it 180, and continue the process.

Step 10:
If we divide 180 by 21, we get 8 and a remainder of 12.
Use 8 as the next digit of our solution. 
Result so far: 3793737.28
If we subtract 168 from 180, we get 12.
Since there are no more digits in the dividend, we add a zero to the remainder making it 120, and continue the process.

Going ahead to step 11:
If we divide 120 by 21, we get 5 and a remainder of 15.
The next digit of our result is 5. 
Result so far: 3793737.285
If we subtract 105 from 120, we get 15.
Since there are no more digits in the dividend, we add a zero to the remainder making it 150, and continue the process.

Let's proceed to step 12:
21 goes into 150 7 times with a remainder of 3.
Use 7 as the next digit of our solution. 
Result so far: 3793737.2857
Subtracting 147 from 150 leaves us 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.

Let's proceed to step 13:
If we divide 30 by 21, we get 1 and a remainder of 9.
Use 1 as the next digit of our solution. 
Result so far: 3793737.28571
Deduct 21 from 30 and we're left with 9.
Since there are no more digits in the dividend, we add a zero to the remainder making it 90, and continue the process.

Advancing to step 14:
If we divide 90 by 21, we get 4 and a remainder of 6.
The next digit of our result is 4. 
Result so far: 3793737.285714
If we subtract 84 from 90, we get 6.
Since there are no more digits in the dividend, we add a zero to the remainder making it 60, and continue the process.

Step 15:
21 goes into 60 2 times with a remainder of 18.
The next digit of our result is 2. 
Result so far: 3793737.2857142
Subtracting 42 from 60 leaves us with 18.
Since there are no more digits in the dividend, we add a zero to the remainder making it 180, and continue the process.

On to step 16:
21 goes into 180 8 times with a remainder of 12.
The number 8 becomes the next digit in our result. 
Result so far: 3793737.28571428
Subtracting 168 from 180 leaves us with 12.
Since there are no more digits in the dividend, we add a zero to the remainder making it 120, and continue the process.

The final result is 3793737.28571428 with a remainder of 1.2e-08.