We look at the division of 70836413 by 643 
The aim is to understand the frequency of 643 in 70836413.

On to step 1:
7 divided by 643 is 0 with a remainder of 7.
The next digit of our result is 0. 
Result so far: 0.0
Subtract 0 from 7 to get 7.
Take the next digit (0) from the dividend and append it to 7, then repeat: 70 / 643

Let's proceed to step 2:
643 goes into 70 0 times with a remainder of 70.
Put 0 as the next digit of the answer. 
Result so far: 0.0
If we take 0 away from 70, we end up with 70.
Append the next digit (8) from the dividend to 70 and continue with: 708 / 643

On to step 3:
The number 643 fits into 708 1 times, leaving a remainder of 65.
The number 1 becomes the next digit in our result. 
Result so far: 1.0
Subtract 643 from 708 to get 65.
Include the next digit (3) from the dividend after 65, then repeat: 653 / 643

Going ahead to step 4:
The number 643 fits into 653 1 times, leaving a remainder of 10.
Put 1 as the next digit of the answer. 
Result so far: 11.0
Subtracting 643 from 653 leaves us with 10.
Include the next digit (6) from the dividend after 10, then repeat: 106 / 643

On to step 5:
643 can be fit into 106 0 times, resulting in a remainder of 106.
The next digit of our result is 0. 
Result so far: 110.0
If we take 0 away from 106, we end up with 106.
Grab the next digit (4) from the dividend, add it to 106, then carry on: 1064 / 643

Going ahead to step 6:
When dividing 1064 by 643, we get 1 with a remainder of 421.
The number 1 becomes the next digit in our result. 
Result so far: 1101.0
If we take 643 away from 1064, we end up with 421.
Append the next digit (1) from the dividend to 421 and continue with: 4211 / 643

Going ahead to step 7:
When dividing 4211 by 643, we get 6 with a remainder of 353.
The next digit of our result is 6. 
Result so far: 11016.0
The remainder is 353 after subtracting 3858 from 4211.
Bring next digit (3) of the dividend behind the 353 and repeat the process: 3533 / 643

Moving on to step 8:
If we divide 3533 by 643, we get 5 and a remainder of 318.
The number 5 becomes the next digit in our result. 
Result so far: 110165.0
If we take 3215 away from 3533, we end up with 318.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3180, and continue the process.

Moving on to step 9:
3180 divided by 643 is 4 with a remainder of 608.
Put 4 as the next digit of the answer. 
Result so far: 110165.4
Subtracting 2572 from 3180 leaves us with 608.
Since there are no more digits in the dividend, we add a zero to the remainder making it 6080, and continue the process.

On to step 10:
643 can be fit into 6080 9 times, resulting in a remainder of 293.
Use 9 as the next digit of our solution. 
Result so far: 110165.49
If we subtract 5787 from 6080, we get 293.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2930, and continue the process.

Moving on to step 11:
643 goes into 2930 4 times with a remainder of 358.
Use 4 as the next digit of our solution. 
Result so far: 110165.494
Deduct 2572 from 2930 and we're left with 358.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3580, and continue the process.

Advancing to step 12:
The number 643 fits into 3580 5 times, leaving a remainder of 365.
Put 5 as the next digit of the answer. 
Result so far: 110165.4945
If we take 3215 away from 3580, we end up with 365.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3650, and continue the process.

Going ahead to step 13:
If we divide 3650 by 643, we get 5 and a remainder of 435.
Put 5 as the next digit of the answer. 
Result so far: 110165.49455
If we take 3215 away from 3650, we end up with 435.
Since there are no more digits in the dividend, we add a zero to the remainder making it 4350, and continue the process.

Our division results in 110165.49455 with a remaining 0.000435.