My grandsons LOVE the metric system. Which is a larger wrench a 10 or
an 11? Which is larger 9/32 or 5/16?

They complain when I grill them on fractions. One of these guys
breezed through calculus and thought it was too easy; this same guy is
helping (major help!) me build the RV and always has to stop and think
about which which wrench or drill bit or ... well you get the idea.

Which is larger a peck or a bushel?

An ounce is an ounce is an ounce, right? And a pound is a pound is a
pound. NOT. A pound of gold weighs less than a pound of lead. Go
figure. What part of an ounce is a carat?

Doc Custer
Retired software engineer and sometime Audiologist
Building RV9-A. Fuselage


"A pound of gold weighs less than a pound of lead."

No it does not Doc :) Gold per cubic inch is heavier
than lead per cubic inch. It is called higher density.
Next thing will happen somebody will say a pound of feathers
is lighter than a pound of gold :)

A pound is equal to about a buck eighty.

There are fluid ounces and ounces in weight.
A fluid ounce is a volume.

Is that a US peck or a UK peck?
1 peck [US] = 0.25 bushel [US, dry]

Which ounce are you talking about?

1 ounce = 141.747 615 625 carat [international]
1 ounce = 141.747 615 625 carat [metric]
1 ounce = 109.375 carat [UK]
1 ounce = 138.088 276 303 carat [pre-1913 US]
1 ounce [troy] = 151.502 566 001 carat [pre-1913 US]
1 ounce [troy] = 120 carat [UK]
1 ounce [troy] = 155.517 384 carat [metric]
1 ounce [troy] = 155.517 384 carat [international]
1 ounce-force = 2.834952313e-8 gigagram
1 ounce-force = 28.349 523 125 gram
1 ounce-force = 0.062 5 lb,lbs
1 ounce-force = 0.278 013 852 Newton
1 ounce-force = 18.229 166 667 pennyweight [troy]
1 ounce [US, liquid] = 2.397565036e-8 acre foot
1 ounce [US, liquid] = 0.000 206 516 barrel [UK, wine]
1 ounce [US, liquid] = 0.000 180 702 barrel [UK]
1 ounce [US, liquid] = 0.000 248 016 barrel [US, liquid]
1 ounce [US, liquid] = 0.007 812 5 gallon [US, liquid]
1 ounce [US, liquid] = 0.031 25 quart [US, liquid] 1/32


You get the idea.

Fractions are easy. Always multiply top and bottom
by the same number until all bottoms are equal
and then look at the top to see which is larger.

10/32 (5/16) is larger than 9/32.

Then adding and subtracting becomes easy.
The problem is the teacher.

This is what I use. With Linux it is running all of the time in
one of the 36 virtual screens. http://www.onlineconversion.com/

You handicapped Windows blokes can use the free Firefox browser
and run it all of the time in one of half  a dozen "tabs".
Not as nice as virtual screens but it is a start.

Paul Lamar ...No rotor no motor.

A pound of gold (troy) weighs less (in grams) than a pound of lead (in
grams) or anything else in the avoirdupois system of weights. In the
troy system, used for precious metals etc., there are only 12 ounces
per pound! What a system! Can anyone say irregular? :(

Doc Custer
Retired software engineer and sometime Audiologist
Building RV9-A. Fuselage

But a troy pound of lead weighs the same as troy pound of gold :)
You are mixing apples and oranges :)

Paul Lamar

Well of course. You have to know and specify which system you are
using and the implications therein otherwise there is likely to be a
misunderstanding. That is the whole point. The US nee English system
of weights and measures has a vast array of weights/measures with many
irregularities and inconsistencies, with conversion factors that are
neither obvious or intuitive. The metric system has basically one: the
gram, centimeter and second from which the others (e.g., liter) are
derived; the conversion factors are usually obvious and intuitive.

We got to the moon with inches. Not furlongs or feet and inches or ...
Most engineers regularize the English system of measures (length) by,
for example, using only inches or feet (not both at the same time) and
decimal fractions thereof. One can speculate that we have 1/2, 1/4,
1/8, 1/16, 1/32, 1/64 and 1/128 of an inch because halving something
with primitive instruments (straight edge and compass) is much easier
than dividing by 10.

The US DOT uses pounds, not tons because there are two different tons,
one weighing 2,000 pounds and one weighing 2,200 pounds. So heavy
trucks are labeled as being, for example 80,000 pounds gross vehicle
combined weight. Would save a lot of labeling paint to simply use 40
tons. :)

It is really hard to defend our common (English) system of weights and
measures on a technical basis.

The politics of the situation demand that we continue to use both
metric and English measures. So every auto mechanic has to have both
sets of tools: metric and English/US. Children brought up using the
grain, ounce, pound, teaspoon, cup, gallon, etc. system must learn the
metric system when they study Chemistry or Physics. So we penalize our
engineers and scientists by requiring them to learn both. Sigh. Isn't
politics wonderful?

Down with specific gravity! Up with density! :)

Doc Custer
Retired software engineer and sometime Audiologist
Building RV9-A. Fuselage

Doc,
How come you chaps don't use Stone i.e. 14 lbs =1 Stone!?
We have an instant mental image of someone's size when given height in feet
and weight in stone. The US system seems to have dropped stone completely.
George ( down under)


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