How do you place the decimal point in the quotient when dividing a decimal by a whole number?

Answer 1

The decimal point goes in the quotient the moment you reach the decimal point in the dividend and need to use the digit in the tenths column. When using the "Bus stop" method, the digits will line up so that the decimal point goes in the quotient directly above the decimal point in the dividend.

Using the Bus stop method, it is easiest to put the decimal point in the quotient above the decimal point in the dividend first (before any any division calculation is done) and then do the division by ignoring the decimal points and putting digits in the quotient as normal; except if once all the digits of the dividend have been used there is a non-zero remainder, zeros can be added to the end of the dividend as they are trailing zeros after a decimal point which make no difference to the number.

eg dividing 1.2 by 5:

First place the decimal point in the quotient over the decimal point in the dividend:

_____._

__------

5_|_1.2

Now divide as normal:

____0.2

__------

5_|_1.2

____1 0

____----

______2

Used up all the digits of the dividend but have a remainder, so add trailing zeros after the decimal point and finish the division:

____0.24

__--------

5_|_1.2000

____1 0

____----

______20

______20

______---

_______0

Only needed one extra 0, but it did not hurt putting three of them.

→ 1.2 ÷ 5 = 0.24

Sometimes the decimal may recur or not terminate; in that case, stop when the required level of accuracy is reached (rounding by calculating a further digit and using that as the deciding digit).