43121799 ÷ 966 
We want to figure out the number of times 43121799 can be divided by 966.

Step 1:
When dividing 4 by 966, we get 0 with a remainder of 4.
The next digit of our result is 0. 
Result so far: 0.0
Deduct 0 from 4 and we're left with 4.
Bring next digit (3) of the dividend behind the 4 and repeat the process: 43 / 966

On to step 2:
966 can be fit into 43 0 times, resulting in a remainder of 43.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
Subtracting 0 from 43 leaves us with 43.
Grab the next digit (1) from the dividend, add it to 43, then carry on: 431 / 966

Going ahead to step 3:
The number 966 fits into 431 0 times, leaving a remainder of 431.
Use 0 as the next digit of our solution. 
Result so far: 0.0
If we take 0 away from 431, we end up with 431.
Include the next digit (2) from the dividend after 431, then repeat: 4312 / 966

On to step 4:
966 goes into 4312 4 times with a remainder of 448.
The number 4 becomes the next digit in our result. 
Result so far: 4.0
Deduct 3864 from 4312 and we're left with 448.
Append the next digit (1) from the dividend to 448 and continue with: 4481 / 966

Moving on to step 5:
If we divide 4481 by 966, we get 4 and a remainder of 617.
The next digit of our result is 4. 
Result so far: 44.0
Subtracting 3864 from 4481 leaves us with 617.
Append the next digit (7) from the dividend to 617 and continue with: 6177 / 966

Let's proceed to step 6:
If we divide 6177 by 966, we get 6 and a remainder of 381.
The number 6 becomes the next digit in our result. 
Result so far: 446.0
Deduct 5796 from 6177 and we're left with 381.
Append the next digit (9) from the dividend to 381 and continue with: 3819 / 966

Moving on to step 7:
966 goes into 3819 3 times with a remainder of 921.
Put 3 as the next digit of the answer. 
Result so far: 4463.0
Subtracting 2898 from 3819 leaves us with 921.
Bring next digit (9) of the dividend behind the 921 and repeat the process: 9219 / 966

Moving on to step 8:
9219 divided by 966 is 9 with a remainder of 525.
The next digit of our result is 9. 
Result so far: 44639.0
The remainder is 525 after subtracting 8694 from 9219.
Since there are no more digits in the dividend, we add a zero to the remainder making it 5250, and continue the process.

On to step 9:
The number 966 fits into 5250 5 times, leaving a remainder of 420.
Record the quotient 5 as the next digit in the result. 
Result so far: 44639.5
If we subtract 4830 from 5250, we get 420.
Since there are no more digits in the dividend, we add a zero to the remainder making it 4200, and continue the process.

Advancing to step 10:
966 can be fit into 4200 4 times, resulting in a remainder of 336.
Put 4 as the next digit of the answer. 
Result so far: 44639.54
Subtracting 3864 from 4200 leaves us with 336.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3360, and continue the process.

On to step 11:
966 goes into 3360 3 times with a remainder of 462.
Put 3 as the next digit of the answer. 
Result so far: 44639.543
Deduct 2898 from 3360 and we're left with 462.
Since there are no more digits in the dividend, we add a zero to the remainder making it 4620, and continue the process.

Going ahead to step 12:
966 can be fit into 4620 4 times, resulting in a remainder of 756.
The number 4 becomes the next digit in our result. 
Result so far: 44639.5434
If we subtract 3864 from 4620, we get 756.
Since there are no more digits in the dividend, we add a zero to the remainder making it 7560, and continue the process.

Moving on to step 13:
The number 966 fits into 7560 7 times, leaving a remainder of 798.
The next digit of our result is 7. 
Result so far: 44639.54347
The remainder is 798 after subtracting 6762 from 7560.
Since there are no more digits in the dividend, we add a zero to the remainder making it 7980, and continue the process.

Step 14:
966 goes into 7980 8 times with a remainder of 252.
The number 8 becomes the next digit in our result. 
Result so far: 44639.543478
Subtracting 7728 from 7980 leaves us with 252.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2520, and continue the process.

Advancing to step 15:
When dividing 2520 by 966, we get 2 with a remainder of 588.
Write down 2 as next digit of the result. 
Result so far: 44639.5434782
Subtracting 1932 from 2520 leaves us with 588.
Since there are no more digits in the dividend, we add a zero to the remainder making it 5880, and continue the process.

Step 16:
If we divide 5880 by 966, we get 6 and a remainder of 84.
Write down 6 as next digit of the result. 
Result so far: 44639.54347826
If we subtract 5796 from 5880, we get 84.
Since there are no more digits in the dividend, we add a zero to the remainder making it 840, and continue the process.

Our division results in 44639.54347826 with a remaining 8.4e-08.