78839402 ÷ 221 
Our goal is to divide 78839402 by 221.

Moving on to step 1:
When dividing 7 by 221, we get 0 with a remainder of 7.
Put 0 as the next digit of the answer. 
Result so far: 0.0
Deduct 0 from 7 and we're left with 7.
Fetch the next digit (8) from the dividend, attach it to 7 and continue: 78 / 221

Moving on to step 2:
221 goes into 78 0 times with a remainder of 78.
The next digit of our result is 0. 
Result so far: 0.0
If we subtract 0 from 78, we get 78.
Append the next digit (8) from the dividend to 78 and continue with: 788 / 221

Moving on to step 3:
When dividing 788 by 221, we get 3 with a remainder of 125.
The number 3 becomes the next digit in our result. 
Result so far: 3.0
If we take 663 away from 788, we end up with 125.
Bring next digit (3) of the dividend behind the 125 and repeat the process: 1253 / 221

Let's proceed to step 4:
1253 divided by 221 is 5 with a remainder of 148.
Use 5 as the next digit of our solution. 
Result so far: 35.0
The remainder is 148 after subtracting 1105 from 1253.
Include the next digit (9) from the dividend after 148, then repeat: 1489 / 221

Let's proceed to step 5:
221 can be fit into 1489 6 times, resulting in a remainder of 163.
Record the quotient 6 as the next digit in the result. 
Result so far: 356.0
Subtracting 1326 from 1489 leaves us with 163.
Fetch the next digit (4) from the dividend, attach it to 163 and continue: 1634 / 221

Advancing to step 6:
221 can be fit into 1634 7 times, resulting in a remainder of 87.
Put 7 as the next digit of the answer. 
Result so far: 3567.0
If we take 1547 away from 1634, we end up with 87.
Include the next digit (0) from the dividend after 87, then repeat: 870 / 221

Let's proceed to step 7:
The number 221 fits into 870 3 times, leaving a remainder of 207.
The number 3 becomes the next digit in our result. 
Result so far: 35673.0
The remainder is 207 after subtracting 663 from 870.
Include the next digit (2) from the dividend after 207, then repeat: 2072 / 221

Step 8:
2072 divided by 221 is 9 with a remainder of 83.
The next digit of our result is 9. 
Result so far: 356739.0
If we subtract 1989 from 2072, we get 83.
Since there are no more digits in the dividend, we add a zero to the remainder making it 830, and continue the process.

Going ahead to step 9:
When dividing 830 by 221, we get 3 with a remainder of 167.
The number 3 becomes the next digit in our result. 
Result so far: 356739.3
Deduct 663 from 830 and we're left with 167.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1670, and continue the process.

Step 10:
221 goes into 1670 7 times with a remainder of 123.
Write down 7 as next digit of the result. 
Result so far: 356739.37
If we take 1547 away from 1670, we end up with 123.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1230, and continue the process.

Going ahead to step 11:
If we divide 1230 by 221, we get 5 and a remainder of 125.
The next digit of our result is 5. 
Result so far: 356739.375
Subtract 1105 from 1230 to get 125.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1250, and continue the process.

Let's proceed to step 12:
1250 divided by 221 is 5 with a remainder of 145.
The next digit of our result is 5. 
Result so far: 356739.3755
If we take 1105 away from 1250, we end up with 145.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1450, and continue the process.

Our division results in 356739.3755 with a remaining 0.00145.