21155 ÷ 7 
We want to divide 21155 by 7.

Let's proceed to step 1:
2 divided by 7 is 0 with a remainder of 2.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
Subtracting 0 from 2 leaves us with 2.
Bring next digit (1) of the dividend behind the 2 and repeat the process: 21 / 7

On to step 2:
When dividing 21 by 7, we get 3 with a remainder of 0.
Record the quotient 3 as the next digit in the result. 
Result so far: 3.0
If we subtract 21 from 21, we get 0.
Bring next digit (1) of the dividend behind the 0 and repeat the process: 1 / 7

Going ahead to step 3:
The number 7 fits into 1 0 times, leaving a remainder of 1.
Record the quotient 0 as the next digit in the result. 
Result so far: 30.0
Subtracting 0 from 1 leaves us with 1.
Bring next digit (5) of the dividend behind the 1 and repeat the process: 15 / 7

On to step 4:
If we divide 15 by 7, we get 2 and a remainder of 1.
Write down 2 as next digit of the result. 
Result so far: 302.0
Subtracting 14 from 15 leaves us with 1.
Take the next digit (5) from the dividend and append it to 1, then repeat: 15 / 7

Advancing to step 5:
7 can be fit into 15 2 times, resulting in a remainder of 1.
Put 2 as the next digit of the answer. 
Result so far: 3022.0
Subtract 14 from 15 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.

Let's proceed to step 6:
7 goes into 10 1 times with a remainder of 3.
Put 1 as the next digit of the answer. 
Result so far: 3022.1
The remainder is 3 after subtracting 7 from 10.
Since there are no more digits in the dividend, we add a zero to the remainder making it 30, and continue the process.

Moving on to step 7:
7 can be fit into 30 4 times, resulting in a remainder of 2.
Put 4 as the next digit of the answer. 
Result so far: 3022.14
If we take 28 away from 30, we end up with 2.
Since there are no more digits in the dividend, we add a zero to the remainder making it 20, and continue the process.

Advancing to step 8:
20 divided by 7 is 2 with a remainder of 6.
The next digit of our result is 2. 
Result so far: 3022.142
Subtract 14 from 20 to get 6.
Since there are no more digits in the dividend, we add a zero to the remainder making it 60, and continue the process.

Going ahead to step 9:
When dividing 60 by 7, we get 8 with a remainder of 4.
Put 8 as the next digit of the answer. 
Result so far: 3022.1428
The remainder is 4 after subtracting 56 from 60.
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 10:
The number 7 fits into 40 5 times, leaving a remainder of 5.
The next digit of our result is 5. 
Result so far: 3022.14285
Subtract 35 from 40 to get 5.
Since there are no more digits in the dividend, we add a zero to the remainder making it 50, and continue the process.

Going ahead to step 11:
If we divide 50 by 7, we get 7 and a remainder of 1.
Put 7 as the next digit of the answer. 
Result so far: 3022.142857
If we take 49 away from 50, we end up with 1.
Since there are no more digits in the dividend, we add a zero to the remainder making it 10, and continue the process.

On to step 12:
If we divide 10 by 7, we get 1 and a remainder of 3.
The next digit of our result is 1. 
Result so far: 3022.1428571
If we subtract 7 from 10, we get 3.
Since there are no more digits in the dividend, we add a zero to the remainder making it 30, and continue the process.

Moving on to step 13:
The number 7 fits into 30 4 times, leaving a remainder of 2.
Use 4 as the next digit of our solution. 
Result so far: 3022.14285714
Subtracting 28 from 30 leaves us with 2.
Since there are no more digits in the dividend, we add a zero to the remainder making it 20, and continue the process.

The final result is 3022.14285714 with a remainder of 2e-09.