40573457 ÷ 643 
The aim is to understand the frequency of 643 in 40573457.

On to step 1:
If we divide 4 by 643, we get 0 and a remainder of 4.
The next digit of our result is 0. 
Result so far: 0.0
Subtract 0 from 4 to get 4.
Take the next digit (0) from the dividend and append it to 4, then repeat: 40 / 643

Advancing to step 2:
40 divided by 643 is 0 with a remainder of 40.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
Deduct 0 from 40 and we're left with 40.
Bring next digit (5) of the dividend behind the 40 and repeat the process: 405 / 643

Advancing to step 3:
If we divide 405 by 643, we get 0 and a remainder of 405.
Put 0 as the next digit of the answer. 
Result so far: 0.0
If we subtract 0 from 405, we get 405.
Append the next digit (7) from the dividend to 405 and continue with: 4057 / 643

Step 4:
643 can be fit into 4057 6 times, resulting in a remainder of 199.
Put 6 as the next digit of the answer. 
Result so far: 6.0
If we take 3858 away from 4057, we end up with 199.
Grab the next digit (3) from the dividend, add it to 199, then carry on: 1993 / 643

Step 5:
1993 divided by 643 is 3 with a remainder of 64.
Use 3 as the next digit of our solution. 
Result so far: 63.0
Subtract 1929 from 1993 to get 64.
Take the next digit (4) from the dividend and append it to 64, then repeat: 644 / 643

Advancing to step 6:
644 divided by 643 is 1 with a remainder of 1.
The next digit of our result is 1. 
Result so far: 631.0
If we subtract 643 from 644, we get 1.
Take the next digit (5) from the dividend and append it to 1, then repeat: 15 / 643

Step 7:
When dividing 15 by 643, we get 0 with a remainder of 15.
Put 0 as the next digit of the answer. 
Result so far: 6310.0
If we subtract 0 from 15, we get 15.
Include the next digit (7) from the dividend after 15, then repeat: 157 / 643

On to step 8:
157 divided by 643 is 0 with a remainder of 157.
Put 0 as the next digit of the answer. 
Result so far: 63100.0
If we subtract 0 from 157, we get 157.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1570, and continue the process.

Step 9:
643 can be fit into 1570 2 times, resulting in a remainder of 284.
Use 2 as the next digit of our solution. 
Result so far: 63100.2
If we subtract 1286 from 1570, we get 284.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2840, and continue the process.

Advancing to step 10:
When dividing 2840 by 643, we get 4 with a remainder of 268.
The next digit of our result is 4. 
Result so far: 63100.24
Subtracting 2572 from 2840 leaves us with 268.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2680, and continue the process.

On to step 11:
643 goes into 2680 4 times with a remainder of 108.
Record the quotient 4 as the next digit in the result. 
Result so far: 63100.244
Subtracting 2572 from 2680 leaves us with 108.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1080, and continue the process.

Our division results in 63100.244 with a remaining 0.0108.