We divide 621586 by 12
Our goal is to divide 621586 by 12.

Step 1:
12 can be fit into 6 0 times, resulting in a remainder of 6.
Use 0 as the next digit of our solution. 
Result so far: 0.0
If we subtract 0 from 6, we get 6.
Grab the next digit (2) from the dividend, add it to 6, then carry on: 62 / 12

On to step 2:
12 goes into 62 5 times with a remainder of 2.
Put 5 as the next digit of the answer. 
Result so far: 5.0
If we take 60 away from 62, we end up with 2.
Append the next digit (1) from the dividend to 2 and continue with: 21 / 12

Moving on to step 3:
The number 12 fits into 21 1 times, leaving a remainder of 9.
Put 1 as the next digit of the answer. 
Result so far: 51.0
The remainder is 9 after subtracting 12 from 21.
Append the next digit (5) from the dividend to 9 and continue with: 95 / 12

Let's proceed to step 4:
When dividing 95 by 12, we get 7 with a remainder of 11.
Write down 7 as next digit of the result. 
Result so far: 517.0
Subtract 84 from 95 to get 11.
Grab the next digit (8) from the dividend, add it to 11, then carry on: 118 / 12

On to step 5:
The number 12 fits into 118 9 times, leaving a remainder of 10.
Use 9 as the next digit of our solution. 
Result so far: 5179.0
If we take 108 away from 118, we end up with 10.
Take the next digit (6) from the dividend and append it to 10, then repeat: 106 / 12

Step 6:
106 divided by 12 is 8 with a remainder of 10.
Record the quotient 8 as the next digit in the result. 
Result so far: 51798.0
Subtract 96 from 106 to get 10.
Since there are no more digits in the dividend, we add a zero to the remainder making it 100, and continue the process.

Moving on to step 7:
12 goes into 100 8 times with a remainder of 4.
Record the quotient 8 as the next digit in the result. 
Result so far: 51798.8
Subtract 96 from 100 to get 4.
Since there are no more digits in the dividend, we add a zero to the remainder making it 40, and continue the process.

Let's proceed to step 8:
If we divide 40 by 12, we get 3 and a remainder of 4.
Write down 3 as next digit of the result. 
Result so far: 51798.83
Subtracting 36 from 40 leaves us with 4.
Since there are no more digits in the dividend, we add a zero to the remainder making it 40, and continue the process.

Moving on to step 9:
12 can be fit into 40 3 times, resulting in a remainder of 4.
Record the quotient 3 as the next digit in the result. 
Result so far: 51798.833
Deduct 36 from 40 and we're left with 4.
Since there are no more digits in the dividend, we add a zero to the remainder making it 40, and continue the process.

Our division results in 51798.833 with a remaining 0.0004.