We're dividing 621395 by 351 
The aim is to understand the frequency of 351 in 621395.

Advancing to step 1:
6 divided by 351 is 0 with a remainder of 6.
Write down 0 as next digit of the result. 
Result so far: 0.0
Deduct 0 from 6 and we're left with 6.
Take the next digit (2) from the dividend and append it to 6, then repeat: 62 / 351

Step 2:
When dividing 62 by 351, we get 0 with a remainder of 62.
Put 0 as the next digit of the answer. 
Result so far: 0.0
If we take 0 away from 62, we end up with 62.
Grab the next digit (1) from the dividend, add it to 62, then carry on: 621 / 351

Advancing to step 3:
621 divided by 351 is 1 with a remainder of 270.
The next digit of our result is 1. 
Result so far: 1.0
The remainder is 270 after subtracting 351 from 621.
Take the next digit (3) from the dividend and append it to 270, then repeat: 2703 / 351

Moving on to step 4:
2703 divided by 351 is 7 with a remainder of 246.
Record the quotient 7 as the next digit in the result. 
Result so far: 17.0
Subtract 2457 from 2703 to get 246.
Bring next digit (9) of the dividend behind the 246 and repeat the process: 2469 / 351

Let's proceed to step 5:
The number 351 fits into 2469 7 times, leaving a remainder of 12.
The number 7 becomes the next digit in our result. 
Result so far: 177.0
If we take 2457 away from 2469, we end up with 12.
Take the next digit (5) from the dividend and append it to 12, then repeat: 125 / 351

On to step 6:
351 can be fit into 125 0 times, resulting in a remainder of 125.
The number 0 becomes the next digit in our result. 
Result so far: 1770.0
Subtracting 0 from 125 leaves us with 125.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1250, and continue the process.

On to step 7:
When dividing 1250 by 351, we get 3 with a remainder of 197.
Put 3 as the next digit of the answer. 
Result so far: 1770.3
Subtract 1053 from 1250 to get 197.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1970, and continue the process.

Let's proceed to step 8:
The number 351 fits into 1970 5 times, leaving a remainder of 215.
Write down 5 as next digit of the result. 
Result so far: 1770.35
Subtracting 1755 from 1970 leaves us with 215.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2150, and continue the process.

Step 9:
The number 351 fits into 2150 6 times, leaving a remainder of 44.
Put 6 as the next digit of the answer. 
Result so far: 1770.356
The remainder is 44 after subtracting 2106 from 2150.
Since there are no more digits in the dividend, we add a zero to the remainder making it 440, and continue the process.

On to step 10:
When dividing 440 by 351, we get 1 with a remainder of 89.
Put 1 as the next digit of the answer. 
Result so far: 1770.3561
Subtracting 351 from 440 leaves us with 89.
Since there are no more digits in the dividend, we add a zero to the remainder making it 890, and continue the process.

Let's proceed to step 11:
If we divide 890 by 351, we get 2 and a remainder of 188.
The number 2 becomes the next digit in our result. 
Result so far: 1770.35612
The remainder is 188 after subtracting 702 from 890.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1880, and continue the process.

Advancing to step 12:
351 goes into 1880 5 times with a remainder of 125.
The next digit of our result is 5. 
Result so far: 1770.356125
Deduct 1755 from 1880 and we're left with 125.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1250, and continue the process.

Advancing to step 13:
351 goes into 1250 3 times with a remainder of 197.
Record the quotient 3 as the next digit in the result. 
Result so far: 1770.3561253
If we take 1053 away from 1250, we end up with 197.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1970, and continue the process.

On to step 14:
351 goes into 1970 5 times with a remainder of 215.
The number 5 becomes the next digit in our result. 
Result so far: 1770.35612535
Subtract 1755 from 1970 to get 215.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2150, and continue the process.

The final result is 1770.35612535 with a remainder of 2.15e-07.