How do you convert mm to cm, and kg to mg in metric system?

2 Answers
Jul 19, 2017

Answer:

It's easy enough once you understand the prefixes. It is typically just multiplying and dividing by tens, thousands, millions etc.

Explanation:

In short: because there are 10 mm in each cm, the number will go down by a factor of 10 (thus 47.3 mm = 4.73 cm)

Similarly in 1 kg there are 1000 g hence 1000 000 mg so the number will increase by a factor of 1 million (2.7356 kg = 2735 600 mg)

Fundamentally, you need to understand SI prefixes here and then how to use standard form here and you're good to go. One final point, the c prefix as in cm is not formally part of the Système Internationale (SI) but is very common as a centimetre is such a useful scale for us humans.

Jul 19, 2017

Answer:

Well #"milli"=10^-3#......

Explanation:

...and thus #1*mm-=1xx10^-3*m#

But #"centi"-=10^-2#....and thus #1*cm-=10^-2*m-=10*mm#

On the other hand #k-=10^3#, and #m-=10^-3# (remember that I am ALSO using the abbreviation #"m "-=" metre"#.)

And #1*kg-=1xx10^3*g#, and #1*mg-=1xx10^-3*g#.

And so #1*g-=1000*mg#, and #1*kg-=1000*g=10^6*mg#.

All I am doing is using the multipliers.......(hopefully appropriately)

#"micro"-=10^-6#, #"milli"-=10^-3#, #"centi"-=10^-2#, #"deci"-=10^-1#, #"kilo"-=10^3#.

One usage that is quite common in the UK is the use of #dm^3# for volume, in preference to #"litres"#. Now #1*dm^3-=1*L#, but #10^3*L=1*m^3#, and .............#1*dm^3-=(1xx10^-1*m)^3=10^-3*m^3=1*L# as required.

So how do you remember them? Keep practising, and note your mistakes. We all make mistakes.