We're dividing 121581 by 10 
Our goal is to divide 121581 by 10.

Let's proceed to step 1:
The number 10 fits into 1 0 times, leaving a remainder of 1.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
If we subtract 0 from 1, we get 1.
Append the next digit (2) from the dividend to 1 and continue with: 12 / 10

Let's proceed to step 2:
The number 10 fits into 12 1 times, leaving a remainder of 2.
Write down 1 as next digit of the result. 
Result so far: 1.0
If we subtract 10 from 12, we get 2.
Append the next digit (1) from the dividend to 2 and continue with: 21 / 10

On to step 3:
When dividing 21 by 10, we get 2 with a remainder of 1.
The next digit of our result is 2. 
Result so far: 12.0
Deduct 20 from 21 and we're left with 1.
Take the next digit (5) from the dividend and append it to 1, then repeat: 15 / 10

Let's proceed to step 4:
10 goes into 15 1 times with a remainder of 5.
Put 1 as the next digit of the answer. 
Result so far: 121.0
Deduct 10 from 15 and we're left with 5.
Take the next digit (8) from the dividend and append it to 5, then repeat: 58 / 10

Let's proceed to step 5:
The number 10 fits into 58 5 times, leaving a remainder of 8.
Use 5 as the next digit of our solution. 
Result so far: 1215.0
Subtracting 50 from 58 leaves us with 8.
Append the next digit (1) from the dividend to 8 and continue with: 81 / 10

Moving on to step 6:
The number 10 fits into 81 8 times, leaving a remainder of 1.
Use 8 as the next digit of our solution. 
Result so far: 12158.0
Subtract 80 from 81 to get 1.
Since there are no more digits in the dividend, we add a zero to the remainder making it 10, and continue the process.

Going ahead to step 7:
If we divide 10 by 10, we get 1 and a remainder of 0.
Write down 1 as next digit of the result. 
Result so far: 12158.1
If we subtract 10 from 10, we get 0.
Since there are no more digits in the dividend, we add a zero to the remainder making it 0, and continue the process.

Let's proceed to step 8:
If we divide 0 by 10, we get 0 and a remainder of 0.
Use 0 as the next digit of our solution. 
Result so far: 12158.1
Subtract 0 from 0 to get 0.
Since there are no more digits in the dividend, we add a zero to the remainder making it 0, and continue the process.

Moving on to step 9:
10 can be fit into 0 0 times, resulting in a remainder of 0.
The next digit of our result is 0. 
Result so far: 12158.1
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.

Our division results in 12158.1 with a remaining 0.0.