Easy Metric Tutorial?

[Uffe Kaagaard]

Math Video - Metric Measurement

http://www.mathplayground.com/howto_Metric.html

 

[festoolviking]

Hi

One of these could help you getting started:

http://www.hultafors.se/produkter/matning/meterstockar/meterstockar-tra/tumstock-61/

Festoolviking

 

[Stephen B]

Decameter, hectometer, and kilometer are mostly used to express road distances and property dimensions.

I'm curious especially for folks in Australia, Canada and the UK, do you typically talk acres or hectares when describing land?

Depends which real estate agent you are talking to! As others and I have said on this and other discussions currently covering measurement, imperial measurements are still used particularly in informal language. Examples include 8x10 photographic paper, acres when bragging about size of land, 4x2 when buying 90x45 wood.

 

[mhch]

On occasion I've purposefully used measures like km just to test people if they remember how many places to move the decimal  [laughing]

Suggest editing your earlier post to avoid any confusion.

Did the editing as suggested. Thanks for reminding me what I learnt at school and forgot later.

And by the way, using both imperial and metric is an excellent way to keep our brains in shape ....

 

[Stephen B]

Don't use centimetres!!

Australian timber merchants sell timber in metres.

To fit with relevant building codes, design and building conventions the common lengths are 1.2m, 1.5m, 1.8m, 2.1m,2.4m,2.7m,3.0m,3.3m,3.6m,3.9m,4.2m,4.5m,4.8m,5.1m and 5.4m. The most common  construction lengths are those between 2.1 and 4.8.

(As Reiska and MHCH have said), when the timber gets to the construction site, workshop etc., we use mm because the drawings and plans will be in mm. For example timber would be measured in mm and cut to construct a 2700mm or 2400mm house frame.

This is because using centimetres can risk major errors when you are rushed or tired, such as not cutting say a 2100mm length but cutting one at 21centimetres!!

With apologies to all who have experienced this embarrassment, including me.

 

[JoggleStick]

Decameter, hectometer, and kilometer are mostly used to express road distances and property dimensions.

I'm curious especially for folks in Australia, Canada and the UK, do you typically talk acres or hectares when describing land?

An interesting question.... I started school in 'feet and inches' and changed to metric half way through school... (In Australia)

So, (remember I'm a builder) I talk property (residential house blocks) in m2...

A large 'block' of land would be 700m2. An acre (rounded) is 4000m2. The traditional urban dream is a house on a 1/4acre. The 1000m2 block is a rarity in new subdivisions- many blocks starting from 400m2 so many traditional 1/4 acre blocks are now being sub-divided/developed into dual properties.

I live on a 1300m2 block... But ask me and this is the kicker.... And I will tell you I have a 1/3 acre block....

My kids ( 3 teenagers) only grew up with Metric, yet when measuring their height they busted their boilers to get over 6 foot tall. I'm 6'2" and my middle son 15yo is just on 6'5"... My 13yo daughter is 5'9" and my 17yo son is stoked cause he just made 6'2 1/4'.... And he can't wait to smash 'the ton' (100mph) in his new car...

It's not clear here; but what I'm saying is that this height and speed thing is how my kids naturally speak. They are 100% fluent in Metric, but still choose to speak 'Imperial' because I guess it is more visually expressive... Ie; 6 foot tall is so much easier to visualise than 180cm.

I work and measure 100% Metric, but I often think and speak Imperial.
If I take my boys to work and say want a 3m length of framing timber... I have to ask for a 9 foot length- because they can't visualise 'Metric'....

My neighbour talks in 'axe-handles' or 'rake handles' when describing length's...

I get it...

 

[NERemodeling]

coming from someone who doesn't use the metric system take this with a grain of salt  and correct me if im wrong guys,

one thing to remember when you are used to imperial but working in metric is not to get hung up on exact imperial to metric conversions, lets take a hypothetical side panel for a base cabinet (frameless)

in inches you would want to cut this to 24" wide x 34 1/2" tall

in metric that would be exactly 609.6mm x 876.3    -  trying to cut to this precision would be more frustrating that just sticking to imperial,

instead that same panel in metric would be cut to 610mm x 878mm

make the switch on a particular project, commit to metric and stick with it as bouncing between the two just dosesn't work

John

 

[Sparktrician]

make the switch on a particular project, commit to metric and stick with it as bouncing between the two just dosesn't work

And don't make the switch in the middle of a job or you'll really twist up your thinker. 

[tongue]

 

[Kev]

Decameter, hectometer, and kilometer are mostly used to express road distances and property dimensions.

I'm curious especially for folks in Australia, Canada and the UK, do you typically talk acres or hectares when describing land?

An interesting question.... I started school in 'feet and inches' and changed to metric half way through school... (In Australia)

So, (remember I'm a builder) I talk property (residential house blocks) in m2...

A large 'block' of land would be 700m2. An acre (rounded) is 4000m2. The traditional urban dream is a house on a 1/4acre. The 1000m2 block is a rarity in new subdivisions- many blocks starting from 400m2 so many traditional 1/4 acre blocks are now being sub-divided/developed into dual properties.

I live on a 1300m2 block... But ask me and this is the kicker.... And I will tell you I have a 1/3 acre block....

My kids ( 3 teenagers) only grew up with Metric, yet when measuring their height they busted their boilers to get over 6 foot tall. I'm 6'2" and my middle son 15yo is just on 6'5"... My 13yo daughter is 5'9" and my 17yo son is stoked cause he just made 6'2 1/4'.... And he can't wait to smash 'the ton' (100mph) in his new car...

It's not clear here; but what I'm saying is that this height and speed thing is how my kids naturally speak. They are 100% fluent in Metric, but still choose to speak 'Imperial' because I guess it is more visually expressive... Ie; 6 foot tall is so much easier to visualise than 180cm.

I work and measure 100% Metric, but I often think and speak Imperial.
If I take my boys to work and say want a 3m length of framing timber... I have to ask for a 9 foot length- because they can't visualise 'Metric'....

My neighbour talks in 'axe-handles' or 'rake handles' when describing length's...

I get it...

I must have gone to school near the same time - I was in early primary when the metric switch happened.

I blame Top Gear for the 100mph thing ! My kids are metric ... my son's 180cm, but that's just under 5'11'' btw.

I have no problem visualising both metric and imperial, but hey ... I'm left handed  [big grin]

 

[RC]

Decameter, hectometer, and kilometer are mostly used to express road distances and property dimensions.

I'm sorry, but is this some weird kind of Frenchism? I've never ever seen deci-, deca- or hectometres used for anything else but irritating lower school kids in their math exams.

Area is measured only in square metres (m^2), volume is measured in either decilitres or litres for small quantities (up to a couple of hundred litres) or cubic metres (m^3) above that. One notable special case is car engine size that's usually expressed in litres i.e. a 1.8l engine, but in more exact technical terms it is expressed as cubic centimetres i.e. 1798cm^2 and lenght is measured in real life either in mm, cm, m or km.

Road distances are always in kilometres for longer distances and metres for less than a kilometre.

 

[AlexThePalex]

Decameter, hectometer, and kilometer are mostly used to express road distances and property dimensions.

I'm sorry, but is this some weird kind of Frenchism? I've never ever seen deci-, deca- or hectometres used for anything else but irritating lower school kids in their math exams.

Area is measured only in square metres (m^2), volume is measured in either decilitres or litres for small quantities (up to a couple of hundred litres) or cubic metres (m^3) above that. One notable special case is car engine size that's usually expressed in litres i.e. a 1.8l engine, but in more exact technical terms it is expressed as cubic centimetres i.e. 1798cm^2 and lenght is measured in real life either in mm, cm, m or km.

Road distances are always in kilometres for longer distances and metres for less than a kilometre.

Well, you can't blame people from imperial countries to know which metric values are used a lot or not.

You're basically right, nobody ever uses deci-, deca- or hectometers. I would like to make one addition: when buying property the size of the land is often given in hectare (at least here in Holland) which is a square hectometer.

For woodworking only mm, cm and meters are important.

 

[RC]

Well, to my knowledge France developed the metric system in 1799 so I presume MHCH, whom I was quoting, as a Frenchman would know what he's talking about [wink]

I'm actually honestly curious about someone in the whole wide world actually using those redundant in-between measurement units ???

We also use hectares (100m x 100m) for larger plots of land and square km for forests and really large parks. Though in urban settings plots are usually less than 1000m^2 so hectares are rarely used in anything less than a farm or forest plot of land.

Another funny thing that came to mind is that boats still use knots and nautical miles as measurement units for some historical or compatibility reasons. I would presume that aviation probably uses feet for universal elevation, but don't have first hand knowledge about this.

If its hard for an imperial user to visualize how much is 180cm, I can attest that its just as impossible for me to understand how much is 13/64's of an inch without a calculator. (apparently its about 5mm which I could approximate with my fingers in an instant).

Imperial units for us metrics become really ugly especially with fluid measurements with different ounces and gallons in the US and UK and I guess there's possibly even an ounce that are weight instead of volume(?). Its hell to try to read English language cookbooks and have to double check on which side of the pond it originated from.

Another source of frustration is the apparent lack of any rhyme or rhytm to the consecutive units in imperial i.e. 12" to a foot, 3 feet to a yard, 22 feet to something I've never heard of (chain), 10 chains to another thing I've never heard of (furlong) and 8 furlongs or I guess 220 yards to a mile - there just isn't any logic to these, duh! (info ripped from wikipedia)

 

[Paul G]

Decameter, hectometer, and kilometer are mostly used to express road distances and property dimensions.

I'm sorry, but is this some weird kind of Frenchism? I've never ever seen deci-, deca- or hectometres used for anything else but irritating lower school kids in their math exams.

Area is measured only in square metres (m^2), volume is measured in either decilitres or litres for small quantities (up to a couple of hundred litres) or cubic metres (m^3) above that. One notable special case is car engine size that's usually expressed in litres i.e. a 1.8l engine, but in more exact technical terms it is expressed as cubic centimetres i.e. 1798cm^2 and lenght is measured in real life either in mm, cm, m or km.

Road distances are always in kilometres for longer distances and metres for less than a kilometre.

It's kinda funny hearing a metric user say that certain types of metric is irritating.  Sounds like even there you stick with what is common (mm, cm, m or km) anything that deviates is irritating (dm, dam, hm) even though it only involves shifting a decimal. That's precisely why using metric here is irritating, it isn't common at all.

 

[AlexThePalex]

Well, to my knowledge France developed the metric system in 1799 so I presume MHCH, whom I was quoting, as a Frenchman would know what he's talking about [wink]

Oops, missed that [embarassed]. I should take my nap.

Another funny thing that came to mind is that boats still use knots and nautical miles as measurement units for some historical or compatibility reasons. I would presume that aviation probably uses feet for universal elevation, but don't have first hand knowledge about this.

Yup, aviation and boats still use feet and knots. Funny thing is that a nautical mile is different from a land mile. I'm glad our land and sea kilometers are the same.

 

[Kev]

lets not forget the megametre and the micrometre ... or even the nanometre (for really splitting hairs).

Of course there's lots more ...

Area has a base of "are", which it 100 square metres, so all the prefixes apply ... hectare is hecto (x100) 10,000 square metres.

volume too ... a kilo litre is 1,000 litres - the unit in which JMB buys vintage champagne [wink]

think metre, gram, litre, are, pascal, etc and use the scale prefix.

There are many exceptions (or options if you like) ... a metric tonne is the same as a megagram for example.

When I was being taught the metric system in Oz it was brand new and I think they started by drumming everything into us ... as things have progressed, less is taught and I feel the fundamentals of the metric system are being lost a little.

 

[Paul G]

You're basically right, nobody ever uses deci-, deca- or hectometers. I would like to make one addition: when buying property the size of the land is often given in hectare (at least here in Holland) which is a square hectometer.

If a a square hectometer is a hectare, does that make a square kilometer a kilare?  EDIT: just saw Kev's explanation of an 'are', I wonder why that is so often supplanted with square meter.

 

[darita]

Wow!  Lots of great info.  It looks like there's enough information here to do anything I need done.  I just have to study the posts.  And you're probably right about doing a project totally committed to metric.  I think that's the only way to really get used to using it.  Back to school...
I think what I'm going to have to do to start with, is to have a diagram showing an imperial foot below it's metric equivalent.  That way, I can visually relate the two.

 

[greg mann]

As an engineer, I bounce back and forth between the two systems quite often. Many times even mixing the two within a single design. (However, drawings are always in one set or the other unless dual dimensions are given for when metric is required, such as screw threads. You never mix units unless there is some specific reason, and that includes the metric system too.)

The imperial system is not as bad as popular misconception portrays it. The main benefit of the metric system comes into play only when you need to convert units. If you don't need to convert units, that primary benefit is not terribly important. For example, converting cubic centimeters to liters is very simple, but that is not a conversion that the average person needs to do very often. Converting millimeters to meters is also very easy, but generally speaking, you still don't want to mix units, even when those units are just multiples of 10. Regardless which system you are using, you pick a unit and stick to it throughout.

The most common complaint about the imperial system is fractions. However, that is a "choice" not a "requirement". We "choose" to buy tape measures that are graduated in fractional increments. However, they are also available in decimal divisions too. That's not a fault of the system of measurement. It's just a choice that has been long-standing. Most machinists and engineers work in decimals, not fractions. And in that regard, there is no difference between the systems unless you want to convert to a different unit.

We "choose" to portray measurements in mixed units, such as 10' 3-1/4", as opposed to 123.25", but that is a choice, not a requirement. The same mixing of units could be done in the metric system, but it just isn't done. You will rarely see a mixed unit measurement of 1m 4cm 2mm. Instead, if the precision of millimeters is required, then the entire number is represented in millimeters (1042mm).

Neither system is any more accurate than the other. It is just different units.

Personally, I find it easier to "guesstimate" the length of a board in inches, than I could in centimeters. But that is simply due to familiarity, and the larger size of an inch versus a centimeter.

Rick makes very good points here. To the OP my first thought in terms of advice is to get rid of the fractional calculator and start using decimals. Even if you go to metric at some point, thinking in terms of decimals will help in thinking metric. Rick's point about fractional measurement being a choice is spot on. Even though I use fractional tapes and scales , when I write down dimensions to do math I write them in decimal because the math is soooo much easier. Having been a machinist/manufacturing engineer all my life, and working in both systems pretty much in the manner Rick described above, makes it pretty easy to float back and forth between systems (and convert those pesky fraction into decimal values). Having said that, when my company first started in CNC machining I asked the question, "Which system should we program in?" The advice I was given was to program in the system in which you measure. It seemed like good advice at the time but I do wish I had been advised to, "Get rid of your Imperial measurement tools and do everything in metric."

Like Rick, the hardest part for me is visualizing sizes in metric over the values I use day to day. It is a piece of cake to work in sub-millimeter values as I do that all the time (.025mm, or 25 microns = .001" as an example,at least close enough even in my world). Centimeter callouts are more difficult for me as I feel the need to convert to millimeters before I can visualize that distance. It is getting easier as time goes by to visualize the macro distances butthe simple fact that I uses decimals in Imperial has probably kept me from changing over completely. Tht and the fact that most of the shorter measurements, say, under 12 inches, are pretty much automatic conversions for me anyway.

 

[mhch]

Decameter, hectometer, and kilometer are mostly used to express road distances and property dimensions.

I'm sorry, but is this some weird kind of Frenchism? I've never ever seen deci-, deca- or hectometres used for anything else but irritating lower school kids in their math exams.

Area is measured only in square metres (m^2), volume is measured in either decilitres or litres for small quantities (up to a couple of hundred litres) or cubic metres (m^3) above that. One notable special case is car engine size that's usually expressed in litres i.e. a 1.8l engine, but in more exact technical terms it is expressed as cubic centimetres i.e. 1798cm^2 and lenght is measured in real life either in mm, cm, m or km.

Road distances are always in kilometres for longer distances and metres for less than a kilometre.

Just to clarify things

No idea of how large dimensions were/are measured outside France, so maybe you're right to say I'm using a Frenchism. Weird, I don't know  :  [big grin]  

"double decameter" was designating that 20m long rolled tape device people used for measuring long distances before the measuring laser and other modern tools were invented

Decameter and hectometer were actually used to express property dimensions, specially in the older days. One reason is that in the French countryside, properties were often made of relatively small disconnected pieces (meadows). Hence the need for a smaller unit than the kilometer. Many aging but still official registered documents probably use those units. And I saw some outside school class !!

But yes, they are no longer used by newer modern documents. So weird isn't the word. Outdated is probably more appropriate  

And now to enlighten everyone ....

have a look at the funny English units that existed: http://en.wikipedia.org/wiki/English_units

And also Pint was./is different between England, Scotland, Ireland (in increasing order of volume). There are still some British pubs displaying "here we served beer by the larger Scottish pint" !!
Maybe because some drink more than others .... [big grin] [big grin] [big grin] [big grin]

 

[NuggyBuggy]

In the metric system, for all given units there are a designated set of  multipliers and associated prefixes.  I believe these prefixes and multipliers are taught to pretty much every high school student who takes a science course - since science is done in metric, this "should" be true in the USA as well.

The multipliers are all base-10.  This means that all multipliers are defined as 10x, where x is one of a defined set of integers.  So, for instance, the multiplier 10-3 (= 1/100) is associated with the prefix "c" or "centi-", and means "take the base unit and multiply by 1/100 (= divide by 100)".

Similarly the multiplier 1000 is associated with the prefix "k"/"kilo".  Therefore, a km or kilometer is the distance represented by the base unit meter, multiplied by 1000.

Except for the multipliers close to the base unit (centi, deci, deca, hecto), each multiplier is 1000 times less than the next larger multiplier, and therefore 1000 times more than the next smaller multiplier.  1000 = 103 and 1/1000 = 10-3.

Therefore it is easy to work with measurements of arbitrary scale.  It's easy to figure out, for instance, how many centimeters, for instance, are in a kilometer: it is simply 103/10-2 = 1000/(1/100) = 100 000. 

Contrast this with the imperial system that has multiple scales for the same measurement domain - distance, for instance, is represented ininches, feet, yards, and miles, etc, with varying multipliers between them.  If you want to convert measurements ranging from inches to miles, you need to know 3 essentially arbitrary conversion factors. 

Then , fractional differences are represented in the imperial system in a different base (base-2) than we do our math in (base-10).  So if you want to divide 7/8" by 6, and then measure this off, you have to do fractional arithmetic and then map this to the measurement scale.  Or you find the equivalent distance in, say, 64-ths of an inch, then do the arithmetic.

Finally, in the imperial system one commonly mixes scales for a single measurement ! So operations on these distances require many more steps  than a comparable operations on metric distance.  For instance if you wanted to know how to divide 8' 6" into 7 pieces and express in feet, you'd probably:
- multiply 8 x 12
- add 6
- divide by 7
- divide by 12
Then you  take the quotient  x and the remainder y, and your final answer is x' plus  y".  The problem here is that the imperial system mixes different measurement scales for the same measurement domain.  You can make the exercise even more fun by adding some fraction of an inch to the above distance.

Whereas in the metric system if you wanted to divide a distance of 243cm by 7, and express in meters, you'd just do
243 x 10-3 / 7
or more likely, since you almost certainly know that 243 cm is 2.43 cm, you'd just do
2.43 / 7

You can then represent this distance to any arbitrary scale by simply multiplying (or dividing) by the appropriate multiplier.  Further, adding a fractional distance does not change the computation like it does in the imperial system - you're just adding more numbers after the decimal place.

Probably the worst part about the imperial system is the common mixing of measurement scales on a single measurement.  If all distances were represented in inches, for instance, much of the arithmetic tedium goes away.  But then representing large differences in scale would either require writing down lots of digits, or ultimately adopting a prefix system - and then you'd effectively have a bastardized, watered-down metric system anyways.  Why do many people often express distances larger than one foot, in inches, for instance ?  Because the imperial system makes it a PITA, that's why.