Question

What is 150 mm expressed in decimeters?

Answer 1

`150` mm is `1.50` decimeter

Explanation:

There are `10` decimeters in each meter

and `1000` mm in each meter

Hence there are `1000/10=100` mm in each decimeter

Hence `150` mm is `150/100=1.50` decimeter.

Answer 2

`150 mm div 10 div 10 = 150/(10xx10) = 1.5dm`

Explanation:

Although decimeters exist, they are seldom used in this form.
We prefer to use metres, centimetres and millimetres.

We would say 20 cm rather than 2 dm, although the length is the same.

The conversion between the units of length is by a factor of 10 each time.

Multiply by 10 to covert to the next smaller unit or divide by 10 to change to the next bigger one.

`150 mm div 10 div 10 = 150/(10xx10) = 1.5dm`

However decimetres are important because they offer another link between length and capacity.

A cube that is

`10cmxx 10cmxx 10 cm` is the same as `1 dm^3`

It holds exactly 1 litre.

So we have:

`1 cm^3 = 1cc = 1ml`

`1 dm^3 = 1 litre`

`1 m^3 = 1 Kl`

The conversion factor between these is 1000.