We look at the division of 438403 by 87 
We want to figure out the number of times 438403 can be divided by 87.

Moving on to step 1:
87 goes into 4 0 times with a remainder of 4.
The next digit of our result is 0. 
Result so far: 0.0
The remainder is 4 after subtracting 0 from 4.
Grab the next digit (3) from the dividend, add it to 4, then carry on: 43 / 87

On to step 2:
87 goes into 43 0 times with a remainder of 43.
Write down 0 as next digit of the result. 
Result so far: 0.0
Deduct 0 from 43 and we're left with 43.
Grab the next digit (8) from the dividend, add it to 43, then carry on: 438 / 87

On to step 3:
When dividing 438 by 87, we get 5 with a remainder of 3.
The number 5 becomes the next digit in our result. 
Result so far: 5.0
Subtract 435 from 438 to get 3.
Include the next digit (4) from the dividend after 3, then repeat: 34 / 87

Moving on to step 4:
87 goes into 34 0 times with a remainder of 34.
Use 0 as the next digit of our solution. 
Result so far: 50.0
Subtracting 0 from 34 leaves us with 34.
Bring next digit (0) of the dividend behind the 34 and repeat the process: 340 / 87

Step 5:
87 goes into 340 3 times with a remainder of 79.
Write down 3 as next digit of the result. 
Result so far: 503.0
If we take 261 away from 340, we end up with 79.
Append the next digit (3) from the dividend to 79 and continue with: 793 / 87

On to step 6:
793 divided by 87 is 9 with a remainder of 10.
Write down 9 as next digit of the result. 
Result so far: 5039.0
The remainder is 10 after subtracting 783 from 793.
Since there are no more digits in the dividend, we add a zero to the remainder making it 100, and continue the process.

On to step 7:
If we divide 100 by 87, we get 1 and a remainder of 13.
Use 1 as the next digit of our solution. 
Result so far: 5039.1
If we subtract 87 from 100, we get 13.
Since there are no more digits in the dividend, we add a zero to the remainder making it 130, and continue the process.

Advancing to step 8:
87 goes into 130 1 times with a remainder of 43.
Record the quotient 1 as the next digit in the result. 
Result so far: 5039.11
Deduct 87 from 130 and we're left with 43.
Since there are no more digits in the dividend, we add a zero to the remainder making it 430, and continue the process.

The final result is 5039.11 with a remainder of 0.043.