21998541 ÷ 891 
The aim is to understand the frequency of 891 in 21998541.

Step 1:
891 can be fit into 2 0 times, resulting in 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.
Include the next digit (1) from the dividend after 2, then repeat: 21 / 891

Let's proceed to step 2:
891 goes into 21 0 times with a remainder of 21.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
If we subtract 0 from 21, we get 21.
Take the next digit (9) from the dividend and append it to 21, then repeat: 219 / 891

Step 3:
If we divide 219 by 891, we get 0 and a remainder of 219.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
If we take 0 away from 219, we end up with 219.
Append the next digit (9) from the dividend to 219 and continue with: 2199 / 891

On to step 4:
The number 891 fits into 2199 2 times, leaving a remainder of 417.
The next digit of our result is 2. 
Result so far: 2.0
Deduct 1782 from 2199 and we're left with 417.
Include the next digit (8) from the dividend after 417, then repeat: 4178 / 891

On to step 5:
4178 divided by 891 is 4 with a remainder of 614.
Record the quotient 4 as the next digit in the result. 
Result so far: 24.0
Subtract 3564 from 4178 to get 614.
Include the next digit (5) from the dividend after 614, then repeat: 6145 / 891

Advancing to step 6:
6145 divided by 891 is 6 with a remainder of 799.
Record the quotient 6 as the next digit in the result. 
Result so far: 246.0
If we take 5346 away from 6145, we end up with 799.
Include the next digit (4) from the dividend after 799, then repeat: 7994 / 891

Let's proceed to step 7:
891 can be fit into 7994 8 times, resulting in a remainder of 866.
Put 8 as the next digit of the answer. 
Result so far: 2468.0
If we take 7128 away from 7994, we end up with 866.
Append the next digit (1) from the dividend to 866 and continue with: 8661 / 891

Going ahead to step 8:
891 can be fit into 8661 9 times, resulting in a remainder of 642.
Write down 9 as next digit of the result. 
Result so far: 24689.0
Subtracting 8019 from 8661 leaves us with 642.
Since there are no more digits in the dividend, we add a zero to the remainder making it 6420, and continue the process.

Advancing to step 9:
891 can be fit into 6420 7 times, resulting in a remainder of 183.
Use 7 as the next digit of our solution. 
Result so far: 24689.7
Subtracting 6237 from 6420 leaves us with 183.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1830, and continue the process.

Going ahead to step 10:
The number 891 fits into 1830 2 times, leaving a remainder of 48.
The number 2 becomes the next digit in our result. 
Result so far: 24689.72
Subtracting 1782 from 1830 leaves us with 48.
Since there are no more digits in the dividend, we add a zero to the remainder making it 480, and continue the process.

Advancing to step 11:
If we divide 480 by 891, we get 0 and a remainder of 480.
Put 0 as the next digit of the answer. 
Result so far: 24689.72
Deduct 0 from 480 and we're left with 480.
Since there are no more digits in the dividend, we add a zero to the remainder making it 4800, and continue the process.

On to step 12:
891 can be fit into 4800 5 times, resulting in a remainder of 345.
Use 5 as the next digit of our solution. 
Result so far: 24689.7205
If we take 4455 away from 4800, we end up with 345.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3450, and continue the process.

On to step 13:
If we divide 3450 by 891, we get 3 and a remainder of 777.
Record the quotient 3 as the next digit in the result. 
Result so far: 24689.72053
Subtract 2673 from 3450 to get 777.
Since there are no more digits in the dividend, we add a zero to the remainder making it 7770, and continue the process.

Let's proceed to step 14:
7770 divided by 891 is 8 with a remainder of 642.
Record the quotient 8 as the next digit in the result. 
Result so far: 24689.720538
If we subtract 7128 from 7770, we get 642.
Since there are no more digits in the dividend, we add a zero to the remainder making it 6420, and continue the process.

Step 15:
891 goes into 6420 7 times with a remainder of 183.
Record the quotient 7 as the next digit in the result. 
Result so far: 24689.7205387
Subtract 6237 from 6420 to get 183.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1830, and continue the process.

Let's proceed to step 16:
891 goes into 1830 2 times with a remainder of 48.
The next digit of our result is 2. 
Result so far: 24689.72053872
The remainder is 48 after subtracting 1782 from 1830.
Since there are no more digits in the dividend, we add a zero to the remainder making it 480, and continue the process.

After the division, we end up with 24689.72053872 and a remainder of 4.8e-08.