Let's divide 54377129 by 15
We want to figure out the number of times 54377129 can be divided by 15.

On to step 1:
If we divide 5 by 15, we get 0 and a remainder of 5.
The next digit of our result is 0. 
Result so far: 0.0
The remainder is 5 after subtracting 0 from 5.
Bring next digit (4) of the dividend behind the 5 and repeat the process: 54 / 15

Let's proceed to step 2:
When dividing 54 by 15, we get 3 with a remainder of 9.
Record the quotient 3 as the next digit in the result. 
Result so far: 3.0
Subtracting 45 from 54 leaves us with 9.
Fetch the next digit (3) from the dividend, attach it to 9 and continue: 93 / 15

Advancing to step 3:
15 goes into 93 6 times with a remainder of 3.
Put 6 as the next digit of the answer. 
Result so far: 36.0
Deduct 90 from 93 and we're left with 3.
Bring next digit (7) of the dividend behind the 3 and repeat the process: 37 / 15

On to step 4:
15 can be fit into 37 2 times, resulting in a remainder of 7.
Record the quotient 2 as the next digit in the result. 
Result so far: 362.0
If we subtract 30 from 37, we get 7.
Bring next digit (7) of the dividend behind the 7 and repeat the process: 77 / 15

Advancing to step 5:
When dividing 77 by 15, we get 5 with a remainder of 2.
Write down 5 as next digit of the result. 
Result so far: 3625.0
Subtracting 75 from 77 leaves us with 2.
Append the next digit (1) from the dividend to 2 and continue with: 21 / 15

On to step 6:
15 goes into 21 1 times with a remainder of 6.
The next digit of our result is 1. 
Result so far: 36251.0
If we take 15 away from 21, we end up with 6.
Take the next digit (2) from the dividend and append it to 6, then repeat: 62 / 15

On to step 7:
62 divided by 15 is 4 with a remainder of 2.
Use 4 as the next digit of our solution. 
Result so far: 362514.0
Subtract 60 from 62 to get 2.
Grab the next digit (9) from the dividend, add it to 2, then carry on: 29 / 15

Let's proceed to step 8:
15 can be fit into 29 1 times, resulting in a remainder of 14.
Use 1 as the next digit of our solution. 
Result so far: 3625141.0
The remainder is 14 after subtracting 15 from 29.
Since there are no more digits in the dividend, we add a zero to the remainder making it 140, and continue the process.

Going ahead to step 9:
If we divide 140 by 15, we get 9 and a remainder of 5.
The number 9 becomes the next digit in our result. 
Result so far: 3625141.9
The remainder is 5 after subtracting 135 from 140.
Since there are no more digits in the dividend, we add a zero to the remainder making it 50, and continue the process.

Advancing to step 10:
If we divide 50 by 15, we get 3 and a remainder of 5.
Put 3 as the next digit of the answer. 
Result so far: 3625141.93
The remainder is 5 after subtracting 45 from 50.
Since there are no more digits in the dividend, we add a zero to the remainder making it 50, and continue the process.

Step 11:
The number 15 fits into 50 3 times, leaving a remainder of 5.
Put 3 as the next digit of the answer. 
Result so far: 3625141.933
If we take 45 away from 50, we end up with 5.
Since there are no more digits in the dividend, we add a zero to the remainder making it 50, and continue the process.

The final outcome is 3625141.933, with a leftover of 0.0005.