80975777 ÷ 21 
We're looking to find how many times 21 goes into 80975777.

Let's proceed to step 1:
21 goes into 8 0 times with a remainder of 8.
Put 0 as the next digit of the answer. 
Result so far: 0.0
The remainder is 8 after subtracting 0 from 8.
Include the next digit (0) from the dividend after 8, then repeat: 80 / 21

Going ahead to step 2:
The number 21 fits into 80 3 times, leaving a remainder of 17.
Use 3 as the next digit of our solution. 
Result so far: 3.0
Subtract 63 from 80 to get 17.
Bring next digit (9) of the dividend behind the 17 and repeat the process: 179 / 21

Step 3:
When dividing 179 by 21, we get 8 with a remainder of 11.
Use 8 as the next digit of our solution. 
Result so far: 38.0
Subtract 168 from 179 to get 11.
Take the next digit (7) from the dividend and append it to 11, then repeat: 117 / 21

Advancing to step 4:
21 goes into 117 5 times with a remainder of 12.
Write down 5 as next digit of the result. 
Result so far: 385.0
Subtracting 105 from 117 leaves us with 12.
Take the next digit (5) from the dividend and append it to 12, then repeat: 125 / 21

Moving on to step 5:
21 goes into 125 5 times with a remainder of 20.
The number 5 becomes the next digit in our result. 
Result so far: 3855.0
Subtracting 105 from 125 leaves us with 20.
Grab the next digit (7) from the dividend, add it to 20, then carry on: 207 / 21

Let's proceed to step 6:
If we divide 207 by 21, we get 9 and a remainder of 18.
Put 9 as the next digit of the answer. 
Result so far: 38559.0
Deduct 189 from 207 and we're left with 18.
Include the next digit (7) from the dividend after 18, then repeat: 187 / 21

Going ahead to step 7:
187 divided by 21 is 8 with a remainder of 19.
The next digit of our result is 8. 
Result so far: 385598.0
The remainder is 19 after subtracting 168 from 187.
Append the next digit (7) from the dividend to 19 and continue with: 197 / 21

Moving on to step 8:
When dividing 197 by 21, we get 9 with a remainder of 8.
The number 9 becomes the next digit in our result. 
Result so far: 3855989.0
Subtracting 189 from 197 leaves us with 8.
Since there are no more digits in the dividend, we add a zero to the remainder making it 80, and continue the process.

Going ahead to step 9:
The number 21 fits into 80 3 times, leaving a remainder of 17.
Record the quotient 3 as the next digit in the result. 
Result so far: 3855989.3
If we take 63 away from 80, we end up with 17.
Since there are no more digits in the dividend, we add a zero to the remainder making it 170, and continue the process.

Going ahead to step 10:
When dividing 170 by 21, we get 8 with a remainder of 2.
Put 8 as the next digit of the answer. 
Result so far: 3855989.38
Deduct 168 from 170 and we're left with 2.
Since there are no more digits in the dividend, we add a zero to the remainder making it 20, and continue the process.

On to step 11:
21 can be fit into 20 0 times, resulting in a remainder of 20.
Record the quotient 0 as the next digit in the result. 
Result so far: 3855989.38
Deduct 0 from 20 and we're left with 20.
Since there are no more digits in the dividend, we add a zero to the remainder making it 200, and continue the process.

Advancing to step 12:
If we divide 200 by 21, we get 9 and a remainder of 11.
The number 9 becomes the next digit in our result. 
Result so far: 3855989.3809
Subtracting 189 from 200 leaves us with 11.
Since there are no more digits in the dividend, we add a zero to the remainder making it 110, and continue the process.

Advancing to step 13:
21 can be fit into 110 5 times, resulting in a remainder of 5.
The next digit of our result is 5. 
Result so far: 3855989.38095
The remainder is 5 after subtracting 105 from 110.
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:
When dividing 50 by 21, we get 2 with a remainder of 8.
The number 2 becomes the next digit in our result. 
Result so far: 3855989.380952
Subtracting 42 from 50 leaves us with 8.
Since there are no more digits in the dividend, we add a zero to the remainder making it 80, and continue the process.

Step 15:
21 goes into 80 3 times with a remainder of 17.
Use 3 as the next digit of our solution. 
Result so far: 3855989.3809523
If we take 63 away from 80, we end up with 17.
Since there are no more digits in the dividend, we add a zero to the remainder making it 170, and continue the process.

Step 16:
The number 21 fits into 170 8 times, leaving a remainder of 2.
Record the quotient 8 as the next digit in the result. 
Result so far: 3855989.38095238
Subtract 168 from 170 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.

The final result is 3855989.38095238 with a remainder of 2e-09.