781600 divided by 45 
The aim is to understand the frequency of 45 in 781600.

Let's proceed to step 1:
When dividing 7 by 45, we get 0 with a remainder of 7.
Use 0 as the next digit of our solution. 
Result so far: 0.0
If we subtract 0 from 7, we get 7.
Grab the next digit (8) from the dividend, add it to 7, then carry on: 78 / 45

Step 2:
78 divided by 45 is 1 with a remainder of 33.
Put 1 as the next digit of the answer. 
Result so far: 1.0
Deduct 45 from 78 and we're left with 33.
Include the next digit (1) from the dividend after 33, then repeat: 331 / 45

On to step 3:
The number 45 fits into 331 7 times, leaving a remainder of 16.
The number 7 becomes the next digit in our result. 
Result so far: 17.0
Deduct 315 from 331 and we're left with 16.
Take the next digit (6) from the dividend and append it to 16, then repeat: 166 / 45

Advancing to step 4:
When dividing 166 by 45, we get 3 with a remainder of 31.
Use 3 as the next digit of our solution. 
Result so far: 173.0
Subtract 135 from 166 to get 31.
Fetch the next digit (0) from the dividend, attach it to 31 and continue: 310 / 45

On to step 5:
45 can be fit into 310 6 times, resulting in a remainder of 40.
Write down 6 as next digit of the result. 
Result so far: 1736.0
The remainder is 40 after subtracting 270 from 310.
Append the next digit (0) from the dividend to 40 and continue with: 400 / 45

Let's proceed to step 6:
The number 45 fits into 400 8 times, leaving a remainder of 40.
Put 8 as the next digit of the answer. 
Result so far: 17368.0
Subtract 360 from 400 to get 40.
Since there are no more digits in the dividend, we add a zero to the remainder making it 400, and continue the process.

On to step 7:
When dividing 400 by 45, we get 8 with a remainder of 40.
The number 8 becomes the next digit in our result. 
Result so far: 17368.8
Subtract 360 from 400 to get 40.
Since there are no more digits in the dividend, we add a zero to the remainder making it 400, and continue the process.

Advancing to step 8:
If we divide 400 by 45, we get 8 and a remainder of 40.
Put 8 as the next digit of the answer. 
Result so far: 17368.88
Subtract 360 from 400 to get 40.
Since there are no more digits in the dividend, we add a zero to the remainder making it 400, and continue the process.

The final result is 17368.88 with a remainder of 0.04.