We're dividing 840402 by 4 
Let's see how many times 4 fits into 840402.

Step 1:
When dividing 8 by 4, we get 2 with a remainder of 0.
The next digit of our result is 2. 
Result so far: 2.0
Deduct 8 from 8 and we're left with 0.
Take the next digit (4) from the dividend and append it to 0, then repeat: 4 / 4

On to step 2:
4 goes into 4 1 times with a remainder of 0.
Write down 1 as next digit of the result. 
Result so far: 21.0
If we subtract 4 from 4, we get 0.
Append the next digit (0) from the dividend to 0 and continue with: 0 / 4

Going ahead to step 3:
The number 4 fits into 0 0 times, leaving a remainder of 0.
The next digit of our result is 0. 
Result so far: 210.0
Deduct 0 from 0 and we're left with 0.
Grab the next digit (4) from the dividend, add it to 0, then carry on: 4 / 4

Advancing to step 4:
4 goes into 4 1 times with a remainder of 0.
Use 1 as the next digit of our solution. 
Result so far: 2101.0
The remainder is 0 after subtracting 4 from 4.
Bring next digit (0) of the dividend behind the 0 and repeat the process: 0 / 4

Advancing to step 5:
0 divided by 4 is 0 with a remainder of 0.
Put 0 as the next digit of the answer. 
Result so far: 21010.0
Subtract 0 from 0 to get 0.
Take the next digit (2) from the dividend and append it to 0, then repeat: 2 / 4

Let's proceed to step 6:
4 can be fit into 2 0 times, resulting in a remainder of 2.
Put 0 as the next digit of the answer. 
Result so far: 210100.0
Subtracting 0 from 2 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.

Let's proceed to step 7:
4 goes into 20 5 times with a remainder of 0.
Put 5 as the next digit of the answer. 
Result so far: 210100.5
If we subtract 20 from 20, 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.

Going ahead to step 8:
If we divide 0 by 4, we get 0 and a remainder of 0.
Use 0 as the next digit of our solution. 
Result so far: 210100.5
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.

On to step 9:
4 can be fit into 0 0 times, resulting in a remainder of 0.
Put 0 as the next digit of the answer. 
Result so far: 210100.5
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.

Our division results in 210100.5 with a remaining 0.0.