We look at the division of 687401 by 45 
The aim is to understand the frequency of 45 in 687401.

Let's proceed to step 1:
6 divided by 45 is 0 with a remainder of 6.
The next digit of our result is 0. 
Result so far: 0.0
Subtract 0 from 6 to get 6.
Append the next digit (8) from the dividend to 6 and continue with: 68 / 45

Let's proceed to step 2:
If we divide 68 by 45, we get 1 and a remainder of 23.
Use 1 as the next digit of our solution. 
Result so far: 1.0
Subtract 45 from 68 to get 23.
Append the next digit (7) from the dividend to 23 and continue with: 237 / 45

Going ahead to step 3:
The number 45 fits into 237 5 times, leaving a remainder of 12.
Write down 5 as next digit of the result. 
Result so far: 15.0
Deduct 225 from 237 and we're left with 12.
Append the next digit (4) from the dividend to 12 and continue with: 124 / 45

Step 4:
45 can be fit into 124 2 times, resulting in a remainder of 34.
Write down 2 as next digit of the result. 
Result so far: 152.0
Deduct 90 from 124 and we're left with 34.
Grab the next digit (0) from the dividend, add it to 34, then carry on: 340 / 45

Let's proceed to step 5:
When dividing 340 by 45, we get 7 with a remainder of 25.
Use 7 as the next digit of our solution. 
Result so far: 1527.0
The remainder is 25 after subtracting 315 from 340.
Grab the next digit (1) from the dividend, add it to 25, then carry on: 251 / 45

Going ahead to step 6:
When dividing 251 by 45, we get 5 with a remainder of 26.
The number 5 becomes the next digit in our result. 
Result so far: 15275.0
Subtract 225 from 251 to get 26.
Since there are no more digits in the dividend, we add a zero to the remainder making it 260, and continue the process.

Let's proceed to step 7:
The number 45 fits into 260 5 times, leaving a remainder of 35.
The next digit of our result is 5. 
Result so far: 15275.5
The remainder is 35 after subtracting 225 from 260.
Since there are no more digits in the dividend, we add a zero to the remainder making it 350, and continue the process.

Let's proceed to step 8:
350 divided by 45 is 7 with a remainder of 35.
Put 7 as the next digit of the answer. 
Result so far: 15275.57
Deduct 315 from 350 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.

Advancing to step 9:
The number 45 fits into 350 7 times, leaving a remainder of 35.
Record the quotient 7 as the next digit in the result. 
Result so far: 15275.577
If we take 315 away from 350, we end up 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.

Our division results in 15275.577 with a remaining 0.0035.