We look at the division of 21590654 by 355 
The aim is to understand the frequency of 355 in 21590654.

Let's proceed to step 1:
355 goes into 2 0 times with a remainder of 2.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
Deduct 0 from 2 and we're left with 2.
Include the next digit (1) from the dividend after 2, then repeat: 21 / 355

Going ahead to step 2:
355 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
Subtract 0 from 21 to get 21.
Include the next digit (5) from the dividend after 21, then repeat: 215 / 355

On to step 3:
355 can be fit into 215 0 times, resulting in a remainder of 215.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
Subtract 0 from 215 to get 215.
Append the next digit (9) from the dividend to 215 and continue with: 2159 / 355

Moving on to step 4:
When dividing 2159 by 355, we get 6 with a remainder of 29.
The next digit of our result is 6. 
Result so far: 6.0
The remainder is 29 after subtracting 2130 from 2159.
Bring next digit (0) of the dividend behind the 29 and repeat the process: 290 / 355

Moving on to step 5:
When dividing 290 by 355, we get 0 with a remainder of 290.
Write down 0 as next digit of the result. 
Result so far: 60.0
Deduct 0 from 290 and we're left with 290.
Grab the next digit (6) from the dividend, add it to 290, then carry on: 2906 / 355

Advancing to step 6:
355 can be fit into 2906 8 times, resulting in a remainder of 66.
The number 8 becomes the next digit in our result. 
Result so far: 608.0
If we subtract 2840 from 2906, we get 66.
Bring next digit (5) of the dividend behind the 66 and repeat the process: 665 / 355

Going ahead to step 7:
If we divide 665 by 355, we get 1 and a remainder of 310.
Put 1 as the next digit of the answer. 
Result so far: 6081.0
If we take 355 away from 665, we end up with 310.
Bring next digit (4) of the dividend behind the 310 and repeat the process: 3104 / 355

Step 8:
When dividing 3104 by 355, we get 8 with a remainder of 264.
Write down 8 as next digit of the result. 
Result so far: 60818.0
Subtract 2840 from 3104 to get 264.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2640, and continue the process.

Step 9:
355 goes into 2640 7 times with a remainder of 155.
The next digit of our result is 7. 
Result so far: 60818.7
The remainder is 155 after subtracting 2485 from 2640.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1550, and continue the process.

Going ahead to step 10:
The number 355 fits into 1550 4 times, leaving a remainder of 130.
The number 4 becomes the next digit in our result. 
Result so far: 60818.74
If we subtract 1420 from 1550, we get 130.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1300, and continue the process.

Moving on to step 11:
355 goes into 1300 3 times with a remainder of 235.
The number 3 becomes the next digit in our result. 
Result so far: 60818.743
If we subtract 1065 from 1300, we get 235.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2350, and continue the process.

Moving on to step 12:
When dividing 2350 by 355, we get 6 with a remainder of 220.
Put 6 as the next digit of the answer. 
Result so far: 60818.7436
If we subtract 2130 from 2350, we get 220.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2200, and continue the process.

On to step 13:
2200 divided by 355 is 6 with a remainder of 70.
Record the quotient 6 as the next digit in the result. 
Result so far: 60818.74366
The remainder is 70 after subtracting 2130 from 2200.
Since there are no more digits in the dividend, we add a zero to the remainder making it 700, and continue the process.

The final outcome is 60818.74366, with a leftover of 7e-05.