70415498 divided by 521 
The aim is to understand the frequency of 521 in 70415498.

Let's proceed to step 1:
When dividing 7 by 521, we get 0 with a remainder of 7.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
Subtracting 0 from 7 leaves us with 7.
Grab the next digit (0) from the dividend, add it to 7, then carry on: 70 / 521

Moving on to step 2:
If we divide 70 by 521, we get 0 and a remainder of 70.
The next digit of our result is 0. 
Result so far: 0.0
Subtracting 0 from 70 leaves us with 70.
Fetch the next digit (4) from the dividend, attach it to 70 and continue: 704 / 521

Going ahead to step 3:
521 can be fit into 704 1 times, resulting in a remainder of 183.
The number 1 becomes the next digit in our result. 
Result so far: 1.0
If we subtract 521 from 704, we get 183.
Grab the next digit (1) from the dividend, add it to 183, then carry on: 1831 / 521

Moving on to step 4:
521 can be fit into 1831 3 times, resulting in a remainder of 268.
The next digit of our result is 3. 
Result so far: 13.0
If we take 1563 away from 1831, we end up with 268.
Include the next digit (5) from the dividend after 268, then repeat: 2685 / 521

Moving on to step 5:
521 goes into 2685 5 times with a remainder of 80.
Record the quotient 5 as the next digit in the result. 
Result so far: 135.0
Subtract 2605 from 2685 to get 80.
Take the next digit (4) from the dividend and append it to 80, then repeat: 804 / 521

Step 6:
The number 521 fits into 804 1 times, leaving a remainder of 283.
Put 1 as the next digit of the answer. 
Result so far: 1351.0
Subtract 521 from 804 to get 283.
Bring next digit (9) of the dividend behind the 283 and repeat the process: 2839 / 521

Advancing to step 7:
521 can be fit into 2839 5 times, resulting in a remainder of 234.
Put 5 as the next digit of the answer. 
Result so far: 13515.0
Subtracting 2605 from 2839 leaves us with 234.
Bring next digit (8) of the dividend behind the 234 and repeat the process: 2348 / 521

On to step 8:
521 goes into 2348 4 times with a remainder of 264.
Record the quotient 4 as the next digit in the result. 
Result so far: 135154.0
Subtracting 2084 from 2348 leaves us with 264.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2640, and continue the process.

Going ahead to step 9:
When dividing 2640 by 521, we get 5 with a remainder of 35.
Record the quotient 5 as the next digit in the result. 
Result so far: 135154.5
Deduct 2605 from 2640 and we're left with 35.
Since there are no more digits in the dividend, we add a zero to the remainder making it 350, and continue the process.

Step 10:
When dividing 350 by 521, we get 0 with a remainder of 350.
Write down 0 as next digit of the result. 
Result so far: 135154.5
If we take 0 away from 350, we end up with 350.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3500, and continue the process.

Advancing to step 11:
521 goes into 3500 6 times with a remainder of 374.
The next digit of our result is 6. 
Result so far: 135154.506
Subtract 3126 from 3500 to get 374.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3740, and continue the process.

Let's proceed to step 12:
The number 521 fits into 3740 7 times, leaving a remainder of 93.
Write down 7 as next digit of the result. 
Result so far: 135154.5067
If we subtract 3647 from 3740, we get 93.
Since there are no more digits in the dividend, we add a zero to the remainder making it 930, and continue the process.

Advancing to step 13:
930 divided by 521 is 1 with a remainder of 409.
The number 1 becomes the next digit in our result. 
Result so far: 135154.50671
Subtracting 521 from 930 leaves us with 409.
Since there are no more digits in the dividend, we add a zero to the remainder making it 4090, and continue the process.

Moving on to step 14:
521 goes into 4090 7 times with a remainder of 443.
Put 7 as the next digit of the answer. 
Result so far: 135154.506717
If we subtract 3647 from 4090, we get 443.
Since there are no more digits in the dividend, we add a zero to the remainder making it 4430, and continue the process.

On to step 15:
When dividing 4430 by 521, we get 8 with a remainder of 262.
The next digit of our result is 8. 
Result so far: 135154.5067178
Deduct 4168 from 4430 and we're left with 262.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2620, and continue the process.

Let's proceed to step 16:
If we divide 2620 by 521, we get 5 and a remainder of 15.
The next digit of our result is 5. 
Result so far: 135154.50671785
If we take 2605 away from 2620, we end up with 15.
Since there are no more digits in the dividend, we add a zero to the remainder making it 150, and continue the process.

The final outcome is 135154.50671785, with a leftover of 1.5e-08.