723421 divided by 16 
We want to figure out the number of times 723421 can be divided by 16.

Step 1:
If we divide 7 by 16, we get 0 and a remainder of 7.
Write down 0 as next digit of the result. 
Result so far: 0.0
Subtracting 0 from 7 leaves us with 7.
Bring next digit (2) of the dividend behind the 7 and repeat the process: 72 / 16

On to step 2:
If we divide 72 by 16, we get 4 and a remainder of 8.
Write down 4 as next digit of the result. 
Result so far: 4.0
If we subtract 64 from 72, we get 8.
Bring next digit (3) of the dividend behind the 8 and repeat the process: 83 / 16

Advancing to step 3:
When dividing 83 by 16, we get 5 with a remainder of 3.
Write down 5 as next digit of the result. 
Result so far: 45.0
If we take 80 away from 83, we end up with 3.
Bring next digit (4) of the dividend behind the 3 and repeat the process: 34 / 16

On to step 4:
16 can be fit into 34 2 times, resulting in a remainder of 2.
Put 2 as the next digit of the answer. 
Result so far: 452.0
If we subtract 32 from 34, we get 2.
Grab the next digit (2) from the dividend, add it to 2, then carry on: 22 / 16

On to step 5:
If we divide 22 by 16, we get 1 and a remainder of 6.
Record the quotient 1 as the next digit in the result. 
Result so far: 4521.0
The remainder is 6 after subtracting 16 from 22.
Grab the next digit (1) from the dividend, add it to 6, then carry on: 61 / 16

Going ahead to step 6:
When dividing 61 by 16, we get 3 with a remainder of 13.
Write down 3 as next digit of the result. 
Result so far: 45213.0
The remainder is 13 after subtracting 48 from 61.
Since there are no more digits in the dividend, we add a zero to the remainder making it 130, and continue the process.

Step 7:
16 can be fit into 130 8 times, resulting in a remainder of 2.
Use 8 as the next digit of our solution. 
Result so far: 45213.8
Deduct 128 from 130 and we're left with 2.
Since there are no more digits in the dividend, we add a zero to the remainder making it 20, and continue the process.

Moving on to step 8:
If we divide 20 by 16, we get 1 and a remainder of 4.
The next digit of our result is 1. 
Result so far: 45213.81
Subtract 16 from 20 to get 4.
Since there are no more digits in the dividend, we add a zero to the remainder making it 40, and continue the process.

On to step 9:
The number 16 fits into 40 2 times, leaving a remainder of 8.
The next digit of our result is 2. 
Result so far: 45213.812
Deduct 32 from 40 and we're left with 8.
Since there are no more digits in the dividend, we add a zero to the remainder making it 80, and continue the process.

Advancing to step 10:
When dividing 80 by 16, we get 5 with a remainder of 0.
Write down 5 as next digit of the result. 
Result so far: 45213.8125
If we subtract 80 from 80, 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 11:
0 divided by 16 is 0 with a remainder of 0.
Record the quotient 0 as the next digit in the result. 
Result so far: 45213.8125
If we take 0 away from 0, we end up 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.

On to step 12:
0 divided by 16 is 0 with a remainder of 0.
The next digit of our result is 0. 
Result so far: 45213.8125
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.

Our division results in 45213.8125 with a remaining 0.0.