Anyone good at math?

[ChezCheese:)]

OK, I'm trying to figure out what one factor I can multiply a price given in euros per kg to arrive at the US dollar price per pound. Not doing the exchange and weight translation separately, but one factor I can multiply, say, €3.95 by to get the dollar cost per pound. Let's say for example the exchange rate is €1=$1.14. Now what?

 

[DaveMatthews]

How about this...

https://www.vcalc.com/wiki/pro/US-Dollars-per-Pound-from-Euros-per-Kilo

 

[twy]

1 Euro = 1.14 dollar
1 kg = 2.20462262 pounds

1 Euro/kg * 1kg/2.20462262lb = 0.45359237 Euro/lb

0.45359237 Euro/lb * $1.14/Euro = $0.52/lb

Euro/kg to $/lb multiply by 0.517095302

3.95 Euro/kg = $2.04/lb

Basically: Euro/kg * kg/lb * $/euro = $/lb

I do not vouch for the accuracy of this calculation............

Better yet, use the link.

 

[ChezCheese:)]

OK, so if I multiply any per kilo euro price by .517, then I should get the dollar price per pound (presuming the exchange is 1.14 per euro)?

So if I wanted to not worry about a few pennies this way or that, I could say multiply by .5? (or divide in half, obviously). Is this correct? So if I saw peaches for €4.50 a kilo, that would be roughly $2.25 a pound?

€4.50/kg x .517 = $2.33/lb

Yes, close enough.

 

[ChezCheese:)]

Now how would I do that backwards? Say I'm looking at peaches in the US for 4.50/lb. How do I get the rough per kg euro price? Double it I guess, yes?

 

[dodgeman]

I think the formula is e=mc²

 

[Jeremy McCreary]

Now how would I do that backwards? Say I'm looking at peaches in the US for 4.50/lb. How do I get the rough per kg euro price? Double it I guess, yes?

Yes, just take the reciprocal of the conversion factor (or your approximation of it) to go the other way. So ½ goes to 2.

Many can double or halve numbers in their heads, so rounding this conversion from 0.517 to 0.5 = ½ is a reasonable way to convert without touching your phone.

The relative error is only -0.17/5.17 = -0.033 or about -3%, where the minus sign indicates that you've rounded down. And the error going the other way is roughly +3%. Surely close enough for most purposes.

 

[PedalUma]

Surely close enough for most purposes

Exactly, who for example really cares if for example a car's speedometer is off within 3%. 65 mph x 0.03 = less than 2 mph. But if you are going to Mars and miss it by 3%, that is different. Then you would miss the mark by 4.2 million miles.

 

[PedalUma]

If I want some guacamole and it is $3.24, or $3.44 I don't blink. That's about 3%. Inflation is at 3%. Tariffs are a tax without representation, that is why we had a revolution to create America,

 

[Chargeride]

This is the full story of that tax.

https://www.thoughtco.com/why-britain-attempted-tax-american-colonists-1222028

 

[ChezCheese:)]

So now that I have a factor for quickly figuring €/kg ->$/lb, how do I do €/liter ->$/US gallon?

 

[Jeremy McCreary]

Let the units guide you through the conversion. For this purpose, you can multiply, divide, and regroup the unit symbols as if they were numbers.

$/gal = (€ × $/€) / (L × gal/L) = €/L × ($/€) / (gal/L)

= €/L × K,

where

K = ($/€) / (gal/L) = $/€ × L/gal

is your single conversion factor in terms of the $/€ and L/gal conversions you know.

 

[Chargeride]

Thats the process that turns a million school kids off math..

We can simplify this by inventing another language that you'll need to understand the numbers.

We really need to refresh math.

 

[Jeremy McCreary]

Thats the process that turns a million school kids off math..

Sorry, this strikes a nerve. In the last few decades, popular culture's come around to the view that STEM subjects (science, technology, engineering, and math) are boring and useless — certainly not something a cool kid would show any interest in. It's OK to blow them off. Who needs them, anyway?

Well, for starters, the folks who make all your tech and gear need them. So do the folks who protect you. STEM illiteracy shouldn't be a badge of honor in today's world. It's a mistake.

We can simplify this by inventing another language that you'll need to understand the numbers.

So what language would you use to explain the general pattern behind these conversions? They come up often, and they're easy enough to DIY. You just have resist the urge to run the other way and think for a few minutes. Handy skill to have.

 

[ChezCheese:)]

Funny thing is, I got straight A's in algebra and geometry in high school, simply by doing my homework, and I credit it for my ability to think logically, but I didn't like it. A few years later I thought I'd get one of my distribution credits over with by taking Math 105 or whatever the lowest math class was at the university. They had what they said was an easy entry level placement test to see where you would start out. Not only could I not do it, I didn't want to do it. A few years later, I took a statistics class. Now that was interesting. That was getting meaning out of a platter of numbers. THAT I liked.

Jeremy, what you have there is a bunch of symbols and has no meaning for me. Like, if I were to write a bunch of Urdu at you and say, "See? Easy!" Math is a language you speak. But I don't speak math. I do speak Urdu though

 

[Jeremy McCreary]

Jeremy, what you have there is a bunch of symbols and has no meaning for me. Like, if I were to write a bunch of Urdu at you and say, "See? Easy!" Math is a language you speak. But I don't speak math. I do speak Urdu though

Sorry, really thought those standard symbols (€ for Euros, L for liters, $ for dollars, gal for gallons, €/L for Euros per liter, etc.) would speak for themselves — at least to folks who remember a little algebra. My mistake.

Using symbols instead of words to work out general patterns is a handy tool that must've come up in statistics. Guess symbols can look intimidating even when they're really not.

 

[DaveMatthews]

Sorry, really thought those standard symbols (€ for Euros, L for liters, $ for dollars, gal for gallons, €/L for Euros per liter, etc.) would speak for themselves — at least to folks who remember a little algebra. My mistake.

Using symbols instead of words to work out general patterns is a handy tool that must've come up in statistics. Guess symbols can look intimidating even when they're really not.

You like symbols eh?
OK...

 

[Chargeride]

Sorry, this strikes a nerve. In the last few decades, popular culture's come around to the view that STEM subjects (science, technology, engineering, and math) are boring and useless — certainly not something a cool kid would show any interest in. It's OK to blow them off. Who needs them, anyway?

Well, for starters, the folks who make all your tech and gear need them. So do the folks who protect you. STEM illiteracy shouldn't be a badge of honor in today's world. It's a mistake.



So what language would you use to explain the general pattern behind these conversions? They come up often, and they're easy enough to DIY. You just have resist the urge to run the other way and think for a few minutes. Handy skill to have.

Yes, but the dropout rate is massive and its because of poor teaching methods.
The entire approach needs a rethink, its presented tediously by people who like it and struggle to explain it to people who dont.

 

[Jeremy McCreary]

Yes, but the dropout rate is massive and its because of poor teaching methods.
The entire approach needs a rethink, its presented tediously by people who like it and struggle to explain it to people who dont.

Believe me, STEM educators are trying hard to find new and better ways to teach their subjects. But in a youth culture that generally values none of this and thinks it's totally uncool, it's akin to educating rocks.

In other words, the problem's at least as much a cultural resistance as it is a didactic failure. And it's not just the kids.

In the US, all this occurs against the backdrop of an adult culture that increasingly delegitimizes STEM in favor of — and at the urging of — religious and political demagogues. When adults wearing their STEM phobias as badges of honor are everywhere in the media and real life, kids are going to take that as permission not to bother.

So how do you reshape the prevailing culture into something more STEM receptive? As with the Surron takeover artists, kids and many adults live in their own mutually reinforcing media silos. Odds that pro-STEM youth influencers will somehow emerge seem slim. Ditto for the odds that the adult anti-STEM tide will suddenly reverse.

Not sure how all this will play out, but blaming the educators and ignoring the cultural side of the problem will surely fail.

 

[stompandgo]

You are onto something here. I also see cultural influences as the main barrier in the growth of STEM in today's youth. Culture certainly plays a big part in the explosive growth of Asian students in STEM. It's not by coincidence.

I don't think that you can make STEM "cool enough" to attract today's American youth. My attraction to it 45 years ago was that it was a good way to make a living over time. I don't think that's enough these days. STEM education is incredibly expensive. The cost has increased exponentially, and STEM wages have not. To many young people, the juice isn't worth the squeeze. They would rather spend 24/7 online in the hope that they will become one of the 1% of influencers that can support themselves. Very low barrier of entry, and they're on their device 24/7 anyway. Why not become a millionaire doing that instead? Plus, the whole employer/employee, job for life loyalty factor went out the window years ago. While today's kids don't want to be a "pawn in the machine", they are pawns to Alphabet and Meta. What's the difference?

Two amazing STEM employment opportunities that will be around for a while are space travel and quantum computing. Can a cultural attraction be created for them? I don't see why not. The success of it will come down to attention span and work ethic. It has to be the "the thing" that everyone wants to be involved in, with a measurable reward.

The backstop for this generation are the trades. They have an adjacent connection to STEM, though.