We look at the division of 46689639 by 378 
The aim is to understand the frequency of 378 in 46689639.

Step 1:
If we divide 4 by 378, we get 0 and a remainder of 4.
The next digit of our result is 0. 
Result so far: 0.0
Subtract 0 from 4 to get 4.
Take the next digit (6) from the dividend and append it to 4, then repeat: 46 / 378

Advancing to step 2:
378 can be fit into 46 0 times, resulting in a remainder of 46.
Write down 0 as next digit of the result. 
Result so far: 0.0
If we take 0 away from 46, we end up with 46.
Bring next digit (6) of the dividend behind the 46 and repeat the process: 466 / 378

Step 3:
378 can be fit into 466 1 times, resulting in a remainder of 88.
The number 1 becomes the next digit in our result. 
Result so far: 1.0
Subtracting 378 from 466 leaves us with 88.
Take the next digit (8) from the dividend and append it to 88, then repeat: 888 / 378

Going ahead to step 4:
378 goes into 888 2 times with a remainder of 132.
Use 2 as the next digit of our solution. 
Result so far: 12.0
If we take 756 away from 888, we end up with 132.
Take the next digit (9) from the dividend and append it to 132, then repeat: 1329 / 378

On to step 5:
When dividing 1329 by 378, we get 3 with a remainder of 195.
The number 3 becomes the next digit in our result. 
Result so far: 123.0
Subtracting 1134 from 1329 leaves us with 195.
Fetch the next digit (6) from the dividend, attach it to 195 and continue: 1956 / 378

Advancing to step 6:
378 can be fit into 1956 5 times, resulting in a remainder of 66.
Use 5 as the next digit of our solution. 
Result so far: 1235.0
If we subtract 1890 from 1956, we get 66.
Bring next digit (3) of the dividend behind the 66 and repeat the process: 663 / 378

Going ahead to step 7:
378 can be fit into 663 1 times, resulting in a remainder of 285.
Use 1 as the next digit of our solution. 
Result so far: 12351.0
Subtract 378 from 663 to get 285.
Append the next digit (9) from the dividend to 285 and continue with: 2859 / 378

On to step 8:
The number 378 fits into 2859 7 times, leaving a remainder of 213.
The next digit of our result is 7. 
Result so far: 123517.0
If we take 2646 away from 2859, we end up with 213.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2130, and continue the process.

Advancing to step 9:
378 can be fit into 2130 5 times, resulting in a remainder of 240.
The number 5 becomes the next digit in our result. 
Result so far: 123517.5
If we subtract 1890 from 2130, we get 240.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2400, and continue the process.

On to step 10:
If we divide 2400 by 378, we get 6 and a remainder of 132.
Write down 6 as next digit of the result. 
Result so far: 123517.56
Subtracting 2268 from 2400 leaves us with 132.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1320, and continue the process.

Step 11:
378 can be fit into 1320 3 times, resulting in a remainder of 186.
Use 3 as the next digit of our solution. 
Result so far: 123517.563
Subtract 1134 from 1320 to get 186.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1860, and continue the process.

Step 12:
378 can be fit into 1860 4 times, resulting in a remainder of 348.
The number 4 becomes the next digit in our result. 
Result so far: 123517.5634
Subtract 1512 from 1860 to get 348.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3480, and continue the process.

Step 13:
If we divide 3480 by 378, we get 9 and a remainder of 78.
The number 9 becomes the next digit in our result. 
Result so far: 123517.56349
Subtract 3402 from 3480 to get 78.
Since there are no more digits in the dividend, we add a zero to the remainder making it 780, and continue the process.

Step 14:
If we divide 780 by 378, we get 2 and a remainder of 24.
Put 2 as the next digit of the answer. 
Result so far: 123517.563492
Subtracting 756 from 780 leaves us with 24.
Since there are no more digits in the dividend, we add a zero to the remainder making it 240, and continue the process.

Let's proceed to step 15:
When dividing 240 by 378, we get 0 with a remainder of 240.
Put 0 as the next digit of the answer. 
Result so far: 123517.563492
Deduct 0 from 240 and we're left with 240.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2400, and continue the process.

Going ahead to step 16:
378 can be fit into 2400 6 times, resulting in a remainder of 132.
Put 6 as the next digit of the answer. 
Result so far: 123517.56349206
Subtract 2268 from 2400 to get 132.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1320, and continue the process.

The final result is 123517.56349206 with a remainder of 1.32e-07.