21620321 divided by 640 
The aim is to understand the frequency of 640 in 21620321.

Advancing to step 1:
The number 640 fits into 2 0 times, leaving a remainder of 2.
Put 0 as the next digit of the answer. 
Result so far: 0.0
If we take 0 away from 2, we end up with 2.
Append the next digit (1) from the dividend to 2 and continue with: 21 / 640

Going ahead to step 2:
If we divide 21 by 640, we get 0 and a remainder of 21.
The next digit of our result is 0. 
Result so far: 0.0
The remainder is 21 after subtracting 0 from 21.
Bring next digit (6) of the dividend behind the 21 and repeat the process: 216 / 640

Let's proceed to step 3:
216 divided by 640 is 0 with a remainder of 216.
Put 0 as the next digit of the answer. 
Result so far: 0.0
If we take 0 away from 216, we end up with 216.
Take the next digit (2) from the dividend and append it to 216, then repeat: 2162 / 640

Moving on to step 4:
If we divide 2162 by 640, we get 3 and a remainder of 242.
Write down 3 as next digit of the result. 
Result so far: 3.0
Subtracting 1920 from 2162 leaves us with 242.
Take the next digit (0) from the dividend and append it to 242, then repeat: 2420 / 640

Going ahead to step 5:
2420 divided by 640 is 3 with a remainder of 500.
Put 3 as the next digit of the answer. 
Result so far: 33.0
Subtracting 1920 from 2420 leaves us with 500.
Bring next digit (3) of the dividend behind the 500 and repeat the process: 5003 / 640

Let's proceed to step 6:
If we divide 5003 by 640, we get 7 and a remainder of 523.
Record the quotient 7 as the next digit in the result. 
Result so far: 337.0
If we subtract 4480 from 5003, we get 523.
Bring next digit (2) of the dividend behind the 523 and repeat the process: 5232 / 640

On to step 7:
640 goes into 5232 8 times with a remainder of 112.
Record the quotient 8 as the next digit in the result. 
Result so far: 3378.0
Subtract 5120 from 5232 to get 112.
Append the next digit (1) from the dividend to 112 and continue with: 1121 / 640

Moving on to step 8:
640 can be fit into 1121 1 times, resulting in a remainder of 481.
The next digit of our result is 1. 
Result so far: 33781.0
If we subtract 640 from 1121, we get 481.
Since there are no more digits in the dividend, we add a zero to the remainder making it 4810, and continue the process.

On to step 9:
640 goes into 4810 7 times with a remainder of 330.
Use 7 as the next digit of our solution. 
Result so far: 33781.7
Subtracting 4480 from 4810 leaves us with 330.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3300, and continue the process.

Advancing to step 10:
640 can be fit into 3300 5 times, resulting in a remainder of 100.
Put 5 as the next digit of the answer. 
Result so far: 33781.75
If we take 3200 away from 3300, we end up with 100.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1000, and continue the process.

Moving on to step 11:
The number 640 fits into 1000 1 times, leaving a remainder of 360.
Put 1 as the next digit of the answer. 
Result so far: 33781.751
If we subtract 640 from 1000, we get 360.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3600, and continue the process.

Advancing to step 12:
The number 640 fits into 3600 5 times, leaving a remainder of 400.
Record the quotient 5 as the next digit in the result. 
Result so far: 33781.7515
Subtract 3200 from 3600 to get 400.
Since there are no more digits in the dividend, we add a zero to the remainder making it 4000, and continue the process.

Step 13:
640 goes into 4000 6 times with a remainder of 160.
The next digit of our result is 6. 
Result so far: 33781.75156
Subtracting 3840 from 4000 leaves us with 160.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1600, and continue the process.

Advancing to step 14:
640 can be fit into 1600 2 times, resulting in a remainder of 320.
Put 2 as the next digit of the answer. 
Result so far: 33781.751562
Deduct 1280 from 1600 and we're left with 320.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3200, and continue the process.

Advancing to step 15:
640 can be fit into 3200 5 times, resulting in a remainder of 0.
The next digit of our result is 5. 
Result so far: 33781.7515625
The remainder is 0 after subtracting 3200 from 3200.
Since there are no more digits in the dividend, we add a zero to the remainder making it 0, and continue the process.

Advancing to step 16:
The number 640 fits into 0 0 times, leaving a remainder of 0.
Use 0 as the next digit of our solution. 
Result so far: 33781.7515625
If we take 0 away from 0, we end up 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.

In conclusion, the division gives 33781.7515625 with a balance of 0.0.