We're dividing 645123 by 48 
Let's see how many times 48 fits into 645123.

Step 1:
If we divide 6 by 48, we get 0 and a remainder of 6.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
Deduct 0 from 6 and we're left with 6.
Bring next digit (4) of the dividend behind the 6 and repeat the process: 64 / 48

Let's proceed to step 2:
The number 48 fits into 64 1 times, leaving a remainder of 16.
The next digit of our result is 1. 
Result so far: 1.0
Subtracting 48 from 64 leaves us with 16.
Fetch the next digit (5) from the dividend, attach it to 16 and continue: 165 / 48

Going ahead to step 3:
48 goes into 165 3 times with a remainder of 21.
Put 3 as the next digit of the answer. 
Result so far: 13.0
If we take 144 away from 165, we end up with 21.
Append the next digit (1) from the dividend to 21 and continue with: 211 / 48

Step 4:
48 goes into 211 4 times with a remainder of 19.
The next digit of our result is 4. 
Result so far: 134.0
If we take 192 away from 211, we end up with 19.
Fetch the next digit (2) from the dividend, attach it to 19 and continue: 192 / 48

Let's proceed to step 5:
48 can be fit into 192 4 times, resulting in a remainder of 0.
The number 4 becomes the next digit in our result. 
Result so far: 1344.0
Subtract 192 from 192 to get 0.
Take the next digit (3) from the dividend and append it to 0, then repeat: 3 / 48

Advancing to step 6:
The number 48 fits into 3 0 times, leaving a remainder of 3.
Use 0 as the next digit of our solution. 
Result so far: 13440.0
Subtract 0 from 3 to get 3.
Since there are no more digits in the dividend, we add a zero to the remainder making it 30, and continue the process.

Going ahead to step 7:
48 can be fit into 30 0 times, resulting in a remainder of 30.
Write down 0 as next digit of the result. 
Result so far: 13440.0
Subtracting 0 from 30 leaves us with 30.
Since there are no more digits in the dividend, we add a zero to the remainder making it 300, and continue the process.

Step 8:
300 divided by 48 is 6 with a remainder of 12.
The number 6 becomes the next digit in our result. 
Result so far: 13440.06
If we subtract 288 from 300, we get 12.
Since there are no more digits in the dividend, we add a zero to the remainder making it 120, and continue the process.

Going ahead to step 9:
48 can be fit into 120 2 times, resulting in a remainder of 24.
Put 2 as the next digit of the answer. 
Result so far: 13440.062
Subtract 96 from 120 to get 24.
Since there are no more digits in the dividend, we add a zero to the remainder making it 240, and continue the process.

Advancing to step 10:
48 goes into 240 5 times with a remainder of 0.
The number 5 becomes the next digit in our result. 
Result so far: 13440.0625
The remainder is 0 after subtracting 240 from 240.
Since there are no more digits in the dividend, we add a zero to the remainder making it 0, and continue the process.

Going ahead to step 11:
If we divide 0 by 48, we get 0 and a remainder of 0.
Record the quotient 0 as the next digit in the result. 
Result so far: 13440.0625
If we subtract 0 from 0, we get 0.
Since there are no more digits in the dividend, we add a zero to the remainder making it 0, and continue the process.

Advancing to step 12:
The number 48 fits into 0 0 times, leaving a remainder of 0.
The number 0 becomes the next digit in our result. 
Result so far: 13440.0625
Deduct 0 from 0 and we're left with 0.
Since there are no more digits in the dividend, we add a zero to the remainder making it 0, and continue the process.

The final outcome is 13440.0625, with a leftover of 0.0.