what does this mean 3.6 mm?

Assuming this is a measurement of length then it means 3.6 millimeters, or 0.36 centimeters (cm) or 0.0036 meters.

It means 3.6 mm

This may be written as :-
3 6/10 mm = 3 3/5 mm

If you are asking what mm means, it is a measure in the metric system :-

10 mm = 1 cm
100 cm = 1 m
1000 m = 1 km

The metric system is a most logical system.

3.6 mm means 3.6 millimeters

Just some conversions:

3.6 mm(millimeters) = 0.36 cm(centimeters) or 0.0036 m(meters).


Hope I helped,
Classicgirl

Well, an inch is 2.54cm and 1 cm=10mm. You can roughly figure 1cm by taking the width of your index finger. 1/3 of it (3.3333....mm) is about 3.6mm. For more accuracy, take an inch, divide by 2.54, multiply by 36 then divide by 100 (about 0.142 inches). You can also get a ruler to help you (if it does have cm markings on it)

3 millimeters and 6/10 of another milimeter

mm = millimeter

1 mm = 1/10 cm (0.1 cm)
3.6 mm = 0.36 cm

You'll need a micrometer or a feeler gauge to measure something this accurately.... it's a pretty small length.