90139 ÷ 80 
Let's see how many times 80 fits into 90139.

Advancing to step 1:
The number 80 fits into 9 0 times, leaving a remainder of 9.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
Subtracting 0 from 9 leaves us with 9.
Take the next digit (0) from the dividend and append it to 9, then repeat: 90 / 80

Moving on to step 2:
80 can be fit into 90 1 times, resulting in a remainder of 10.
The next digit of our result is 1. 
Result so far: 1.0
Subtracting 80 from 90 leaves us with 10.
Fetch the next digit (1) from the dividend, attach it to 10 and continue: 101 / 80

On to step 3:
101 divided by 80 is 1 with a remainder of 21.
The number 1 becomes the next digit in our result. 
Result so far: 11.0
If we subtract 80 from 101, we get 21.
Take the next digit (3) from the dividend and append it to 21, then repeat: 213 / 80

Step 4:
When dividing 213 by 80, we get 2 with a remainder of 53.
The number 2 becomes the next digit in our result. 
Result so far: 112.0
If we subtract 160 from 213, we get 53.
Append the next digit (9) from the dividend to 53 and continue with: 539 / 80

Let's proceed to step 5:
539 divided by 80 is 6 with a remainder of 59.
Put 6 as the next digit of the answer. 
Result so far: 1126.0
The remainder is 59 after subtracting 480 from 539.
Since there are no more digits in the dividend, we add a zero to the remainder making it 590, and continue the process.

Step 6:
80 goes into 590 7 times with a remainder of 30.
Use 7 as the next digit of our solution. 
Result so far: 1126.7
If we take 560 away from 590, we end up with 30.
Since there are no more digits in the dividend, we add a zero to the remainder making it 300, and continue the process.

Advancing to step 7:
When dividing 300 by 80, we get 3 with a remainder of 60.
The next digit of our result is 3. 
Result so far: 1126.73
Subtracting 240 from 300 leaves us with 60.
Since there are no more digits in the dividend, we add a zero to the remainder making it 600, and continue the process.

Step 8:
If we divide 600 by 80, we get 7 and a remainder of 40.
The next digit of our result is 7. 
Result so far: 1126.737
Subtract 560 from 600 to get 40.
Since there are no more digits in the dividend, we add a zero to the remainder making it 400, and continue the process.

Advancing to step 9:
The number 80 fits into 400 5 times, leaving a remainder of 0.
The number 5 becomes the next digit in our result. 
Result so far: 1126.7375
If we take 400 away from 400, we end up with 0.
Since there are no more digits in the dividend, we add a zero to the remainder making it 0, and continue the process.

Going ahead to step 10:
0 divided by 80 is 0 with a remainder of 0.
Record the quotient 0 as the next digit in the result. 
Result so far: 1126.7375
Subtracting 0 from 0 leaves us with 0.
Since there are no more digits in the dividend, we add a zero to the remainder making it 0, and continue the process.

On to step 11:
80 can be fit into 0 0 times, resulting in a remainder of 0.
Use 0 as the next digit of our solution. 
Result so far: 1126.7375
Deduct 0 from 0 and we're left with 0.
Since there are no more digits in the dividend, we add a zero to the remainder making it 0, and continue the process.

The final result is 1126.7375 with a remainder of 0.0.