Question

How do you change 75 millimeters to decimeters?

Answer 1

`0.75dm`

Explanation:

The units of the metric system are as follows:

`Kmcolor(white)(xxx)Hmcolor(white)(xxx)Dmcolor(white)(xxx)mcolor(white)(xxx)dmcolor(white)(xxx)cmcolor(white)(xxx)mm`

To convert from one unit to the next is by a factor of 10.

Converting to a smaller unit, the number gets bigger. (multiply)
Converting to a bigger unit, the number gets smaller (divide)

To change from mm to dm you must `div 10 div 10`

`75mm div 10 div 10 = 0.75dm`

You can also convert the units by 'moving' the decimal point.
In this case it must be moved 2 places to the left.

`75.mm rarr 0.75dm`

Answer 2

Build a ladder and count the steps from one unit to the other
The answer is 0.75 dm

Explanation:

The decimal system is based on powers of ten. Build a ladder that looks like this

Km
Hm

              Dm

                         m

                               dm

                                       cm

                                               mm

Looking at the ladder, mm is two to the right and two lower than dm

Move the decimal point two places to the left to get from mm to dm.

giving 0.75 dm