90158987 ÷ 409 
Our goal is to divide 90158987 by 409.

Advancing to step 1:
If we divide 9 by 409, we get 0 and a remainder of 9.
Use 0 as the next digit of our solution. 
Result so far: 0.0
The remainder is 9 after subtracting 0 from 9.
Take the next digit (0) from the dividend and append it to 9, then repeat: 90 / 409

Let's proceed to step 2:
409 goes into 90 0 times with a remainder of 90.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
If we subtract 0 from 90, we get 90.
Append the next digit (1) from the dividend to 90 and continue with: 901 / 409

Step 3:
When dividing 901 by 409, we get 2 with a remainder of 83.
Use 2 as the next digit of our solution. 
Result so far: 2.0
The remainder is 83 after subtracting 818 from 901.
Include the next digit (5) from the dividend after 83, then repeat: 835 / 409

Let's proceed to step 4:
835 divided by 409 is 2 with a remainder of 17.
Record the quotient 2 as the next digit in the result. 
Result so far: 22.0
Subtract 818 from 835 to get 17.
Fetch the next digit (8) from the dividend, attach it to 17 and continue: 178 / 409

On to step 5:
178 divided by 409 is 0 with a remainder of 178.
Put 0 as the next digit of the answer. 
Result so far: 220.0
Subtracting 0 from 178 leaves us with 178.
Append the next digit (9) from the dividend to 178 and continue with: 1789 / 409

Advancing to step 6:
If we divide 1789 by 409, we get 4 and a remainder of 153.
The next digit of our result is 4. 
Result so far: 2204.0
Subtracting 1636 from 1789 leaves us with 153.
Grab the next digit (8) from the dividend, add it to 153, then carry on: 1538 / 409

Let's proceed to step 7:
409 can be fit into 1538 3 times, resulting in a remainder of 311.
Record the quotient 3 as the next digit in the result. 
Result so far: 22043.0
If we subtract 1227 from 1538, we get 311.
Bring next digit (7) of the dividend behind the 311 and repeat the process: 3117 / 409

Moving on to step 8:
The number 409 fits into 3117 7 times, leaving a remainder of 254.
The next digit of our result is 7. 
Result so far: 220437.0
The remainder is 254 after subtracting 2863 from 3117.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2540, and continue the process.

Advancing to step 9:
409 goes into 2540 6 times with a remainder of 86.
Write down 6 as next digit of the result. 
Result so far: 220437.6
Subtracting 2454 from 2540 leaves us with 86.
Since there are no more digits in the dividend, we add a zero to the remainder making it 860, and continue the process.

Moving on to step 10:
409 goes into 860 2 times with a remainder of 42.
The next digit of our result is 2. 
Result so far: 220437.62
Deduct 818 from 860 and we're left with 42.
Since there are no more digits in the dividend, we add a zero to the remainder making it 420, and continue the process.

On to step 11:
409 goes into 420 1 times with a remainder of 11.
Write down 1 as next digit of the result. 
Result so far: 220437.621
Subtracting 409 from 420 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.

Let's proceed to step 12:
When dividing 110 by 409, we get 0 with a remainder of 110.
The number 0 becomes the next digit in our result. 
Result so far: 220437.621
The remainder is 110 after subtracting 0 from 110.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1100, and continue the process.

On to step 13:
409 goes into 1100 2 times with a remainder of 282.
The next digit of our result is 2. 
Result so far: 220437.62102
Deduct 818 from 1100 and we're left with 282.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2820, and continue the process.

Advancing to step 14:
The number 409 fits into 2820 6 times, leaving a remainder of 366.
Use 6 as the next digit of our solution. 
Result so far: 220437.621026
If we subtract 2454 from 2820, we get 366.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3660, and continue the process.

Let's proceed to step 15:
409 can be fit into 3660 8 times, resulting in a remainder of 388.
Record the quotient 8 as the next digit in the result. 
Result so far: 220437.6210268
If we subtract 3272 from 3660, we get 388.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3880, and continue the process.

On to step 16:
The number 409 fits into 3880 9 times, leaving a remainder of 199.
Write down 9 as next digit of the result. 
Result so far: 220437.62102689
If we take 3681 away from 3880, we end up with 199.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1990, and continue the process.

The final result is 220437.62102689 with a remainder of 1.99e-07.