77989807 ÷ 121 
Our goal is to divide 77989807 by 121.

Moving on to step 1:
The number 121 fits into 7 0 times, leaving a remainder of 7.
Write down 0 as next digit of the result. 
Result so far: 0.0
Deduct 0 from 7 and we're left with 7.
Include the next digit (7) from the dividend after 7, then repeat: 77 / 121

Let's proceed to step 2:
The number 121 fits into 77 0 times, leaving a remainder of 77.
The next digit of our result is 0. 
Result so far: 0.0
If we subtract 0 from 77, we get 77.
Include the next digit (9) from the dividend after 77, then repeat: 779 / 121

Let's proceed to step 3:
If we divide 779 by 121, we get 6 and a remainder of 53.
Write down 6 as next digit of the result. 
Result so far: 6.0
Deduct 726 from 779 and we're left with 53.
Bring next digit (8) of the dividend behind the 53 and repeat the process: 538 / 121

Advancing to step 4:
538 divided by 121 is 4 with a remainder of 54.
The next digit of our result is 4. 
Result so far: 64.0
Subtract 484 from 538 to get 54.
Append the next digit (9) from the dividend to 54 and continue with: 549 / 121

Advancing to step 5:
The number 121 fits into 549 4 times, leaving a remainder of 65.
Put 4 as the next digit of the answer. 
Result so far: 644.0
Subtract 484 from 549 to get 65.
Fetch the next digit (8) from the dividend, attach it to 65 and continue: 658 / 121

Step 6:
The number 121 fits into 658 5 times, leaving a remainder of 53.
Use 5 as the next digit of our solution. 
Result so far: 6445.0
Subtracting 605 from 658 leaves us with 53.
Grab the next digit (0) from the dividend, add it to 53, then carry on: 530 / 121

Step 7:
121 goes into 530 4 times with a remainder of 46.
The next digit of our result is 4. 
Result so far: 64454.0
Subtract 484 from 530 to get 46.
Bring next digit (7) of the dividend behind the 46 and repeat the process: 467 / 121

Going ahead to step 8:
The number 121 fits into 467 3 times, leaving a remainder of 104.
The next digit of our result is 3. 
Result so far: 644543.0
If we take 363 away from 467, we end up with 104.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1040, and continue the process.

Going ahead to step 9:
When dividing 1040 by 121, we get 8 with a remainder of 72.
The number 8 becomes the next digit in our result. 
Result so far: 644543.8
Subtract 968 from 1040 to get 72.
Since there are no more digits in the dividend, we add a zero to the remainder making it 720, and continue the process.

Moving on to step 10:
When dividing 720 by 121, we get 5 with a remainder of 115.
Record the quotient 5 as the next digit in the result. 
Result so far: 644543.85
Deduct 605 from 720 and we're left with 115.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1150, and continue the process.

Let's proceed to step 11:
The number 121 fits into 1150 9 times, leaving a remainder of 61.
Write down 9 as next digit of the result. 
Result so far: 644543.859
If we take 1089 away from 1150, we end up with 61.
Since there are no more digits in the dividend, we add a zero to the remainder making it 610, and continue the process.

Step 12:
When dividing 610 by 121, we get 5 with a remainder of 5.
Record the quotient 5 as the next digit in the result. 
Result so far: 644543.8595
Subtract 605 from 610 to 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 13:
If we divide 50 by 121, we get 0 and a remainder of 50.
Record the quotient 0 as the next digit in the result. 
Result so far: 644543.8595
The remainder is 50 after subtracting 0 from 50.
Since there are no more digits in the dividend, we add a zero to the remainder making it 500, and continue the process.

On to step 14:
121 can be fit into 500 4 times, resulting in a remainder of 16.
Write down 4 as next digit of the result. 
Result so far: 644543.859504
Subtracting 484 from 500 leaves us with 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 15:
The number 121 fits into 160 1 times, leaving a remainder of 39.
The next digit of our result is 1. 
Result so far: 644543.8595041
The remainder is 39 after subtracting 121 from 160.
Since there are no more digits in the dividend, we add a zero to the remainder making it 390, and continue the process.

Advancing to step 16:
121 can be fit into 390 3 times, resulting in a remainder of 27.
Put 3 as the next digit of the answer. 
Result so far: 644543.85950413
If we subtract 363 from 390, we get 27.
Since there are no more digits in the dividend, we add a zero to the remainder making it 270, and continue the process.

In conclusion, the division gives 644543.85950413 with a balance of 2.7e-08.