In the last column we discussed a method of division with decimal answers. We discussed division by 9 and by 99. In this article we will look at division by 8 to get decimal answers.
Example: 311 / 8
The base is 10 so we set aside the last digit for remainder, which is where the decimal part of the answer starts. We include three zeroes to get up to the fourth decimal place. The complement is 2.
8 3 1 1 0 0 0
2
Bring the first digit down.
8 3 1 1 0 0 0
2
3
Multiply that by the complement and put the answer below the next digit i.e. 0. Then add 1 + 6 and write the answer below.
8 3 1 1 0 0 0
2 6
3 7
Next multiply 7 by the complement and put the answer below the next digit, 1.
8 3 1 1 0 0 0
2 6 14
3 7
Add 14 + 1 and write the answer below.
8 3 1 1 0 0 0
2 6 14
3 7 15
We repeat the two steps till we have a number below every digit. See below.
8 3 1 1 0 0 0
2 6 14 30 60 120
3 7 15 30 60 120
Since only one digit is allowed in each place, we carry over the surplus digits to the previous place. So 0 is retained, 12 is carried over and added to 60 to give 72. The 2 is retained and 7 added to 30 to give 37 and so on.
3 7 15 30 60 120
3 8 8 7 2 0
Answer: 38.8720
11203 / 898
The base for 898 is 1000 so we set aside the last 3 digits for the decimal part of the answer. We include one zero at the end to get the fourth decimal place. The complement is 102.
898 1 1 2 0 3 0
102
Bring down the first digit. Multiply it by the complement and write the answer below the next digits.
898 1 1 2 0 3 0
102 1 0 2
1 2
Add 1 + 1 and write the answer below the line. Next multiply 2 by the complement and write the answer below the next digits.
898 1 1 2 0 3 0
102 1 0 2
2 0 4
1
Add the digits in the next line and write the answer, 4, below. Multiply 4 by the complement and write the answer below the next digits.
898 1 1 2 0 3 0
102 1 0 2
2 0 4
4 0 8
1 2 4
We have come to the last digit so we simply add the digits vertically and write the answer below.
898 1 1 2 0 3 0
102 1 0 2
2 0 4
4 0 8
1 2 4 6 7 8.
Answer: 12. 4678
You can try these:
1) 113 / 8
2) 111 /89
3) 1234 / 889
4) 10010 / 89
5) 210012 / 8998