Let's divide 421298 by 390
We're looking to find how many times 390 goes into 421298.

On to step 1:
4 divided by 390 is 0 with a remainder of 4.
The next digit of our result is 0. 
Result so far: 0.0
Subtracting 0 from 4 leaves us with 4.
Include the next digit (2) from the dividend after 4, then repeat: 42 / 390

Going ahead to step 2:
The number 390 fits into 42 0 times, leaving a remainder of 42.
The next digit of our result is 0. 
Result so far: 0.0
Deduct 0 from 42 and we're left with 42.
Grab the next digit (1) from the dividend, add it to 42, then carry on: 421 / 390

Advancing to step 3:
If we divide 421 by 390, we get 1 and a remainder of 31.
Write down 1 as next digit of the result. 
Result so far: 1.0
The remainder is 31 after subtracting 390 from 421.
Take the next digit (2) from the dividend and append it to 31, then repeat: 312 / 390

On to step 4:
The number 390 fits into 312 0 times, leaving a remainder of 312.
Put 0 as the next digit of the answer. 
Result so far: 10.0
Subtracting 0 from 312 leaves us with 312.
Take the next digit (9) from the dividend and append it to 312, then repeat: 3129 / 390

Advancing to step 5:
If we divide 3129 by 390, we get 8 and a remainder of 9.
The next digit of our result is 8. 
Result so far: 108.0
Subtracting 3120 from 3129 leaves us with 9.
Append the next digit (8) from the dividend to 9 and continue with: 98 / 390

Going ahead to step 6:
When dividing 98 by 390, we get 0 with a remainder of 98.
Write down 0 as next digit of the result. 
Result so far: 1080.0
The remainder is 98 after subtracting 0 from 98.
Since there are no more digits in the dividend, we add a zero to the remainder making it 980, and continue the process.

Step 7:
980 divided by 390 is 2 with a remainder of 200.
Put 2 as the next digit of the answer. 
Result so far: 1080.2
If we take 780 away from 980, we end up with 200.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2000, and continue the process.

Moving on to step 8:
390 can be fit into 2000 5 times, resulting in a remainder of 50.
The number 5 becomes the next digit in our result. 
Result so far: 1080.25
If we subtract 1950 from 2000, we get 50.
Since there are no more digits in the dividend, we add a zero to the remainder making it 500, and continue the process.

Advancing to step 9:
390 goes into 500 1 times with a remainder of 110.
Put 1 as the next digit of the answer. 
Result so far: 1080.251
The remainder is 110 after subtracting 390 from 500.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1100, and continue the process.

Step 10:
The number 390 fits into 1100 2 times, leaving a remainder of 320.
Record the quotient 2 as the next digit in the result. 
Result so far: 1080.2512
The remainder is 320 after subtracting 780 from 1100.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3200, and continue the process.

On to step 11:
When dividing 3200 by 390, we get 8 with a remainder of 80.
Write down 8 as next digit of the result. 
Result so far: 1080.25128
Subtract 3120 from 3200 to get 80.
Since there are no more digits in the dividend, we add a zero to the remainder making it 800, and continue the process.

Advancing to step 12:
If we divide 800 by 390, we get 2 and a remainder of 20.
Put 2 as the next digit of the answer. 
Result so far: 1080.251282
If we take 780 away from 800, we end up with 20.
Since there are no more digits in the dividend, we add a zero to the remainder making it 200, and continue the process.

Let's proceed to step 13:
390 can be fit into 200 0 times, resulting in a remainder of 200.
Write down 0 as next digit of the result. 
Result so far: 1080.251282
If we subtract 0 from 200, we get 200.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2000, and continue the process.

Step 14:
When dividing 2000 by 390, we get 5 with a remainder of 50.
Put 5 as the next digit of the answer. 
Result so far: 1080.25128205
Subtract 1950 from 2000 to get 50.
Since there are no more digits in the dividend, we add a zero to the remainder making it 500, and continue the process.

After the division, we end up with 1080.25128205 and a remainder of 5e-08.