Math Is Fun Forum

mattb23

Member

Registered: 2007-05-01

Posts: 1

Got A question for everyone :)

Ok, is 1.86 the same as $1.86? When are they the same and what would make them different. Had this question on a math test for a job... wonder if I got it right.

mattb23

Suzeqte

Member

Registered: 2007-05-11

Posts: 0

Re: Got A question for everyone :)

were they asking you in monetary terms?

mathsyperson

Moderator

Registered: 2005-06-22

Posts: 4,900

Re: Got A question for everyone :)

They certainly have the same value, and they'd be the same in an abstract world. But they're not absolutely the same, because one is a number and one is an amount of money.

You could go into a shop and pay for something with $1.86 without any troubles (as long as the item didn't cost more), but if you tried to pay with a bit of paper that had 1.86 written on it then you'd get an odd look and not receive your item.

It's kind of the same reason why 1.86 metres is different from 1.86 inches.

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Why did the vector cross the road?
It wanted to be normal.

MathsIsFun

Administrator

Registered: 2005-01-21

Posts: 7,713

Re: Got A question for everyone :)

And, as an amount, $1.86 has the extra quality of having no more than 2 decimal places.

For example you cannot divide $1.86 by 10 because you cannot pay $0.186

However $0.186 is fine as a *rate* but not a final amount.

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"The physicists defer only to mathematicians, and the mathematicians defer only to God ..."  - Leon M. Lederman

burningleo

Member

Registered: 2007-04-10

Posts: 24

Re: Got A question for everyone :)

  thats funny trying to pay with a peice of paper that says 1.86 on it  but what if it said $1.86 instead of 1.86

Last edited by burningleo (2007-05-18 04:03:28)

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What was, was and whats here is now

Identity

Member

Registered: 2007-04-18

Posts: 934

Re: Got A question for everyone :)

Think of 1.86 as a number, but if you apply it to the real world, it is incomplete. If you want to use a value in the real world, you need to say what TYPE of number it is.

It could be 1.86m, or $1.86, or 1.86kg etc.

It is complete in the 'number' world, but you must specify what type it is to apply it to real world problems.

Last edited by Identity (2007-05-18 14:02:55)

burningleo

Member

Registered: 2007-04-10

Posts: 24

Re: Got A question for everyone :)

i wonder what number worl is like

its a land where 6 is afraid of 7 and 8's are hunted by 12's

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What was, was and whats here is now

olalicious

Member

Registered: 2007-05-22

Posts: 0

Re: Got A question for everyone :)

yea theyre different because 1.86 is a decimal by itself and $1.86 makes it into a currency

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mikau

Member

Registered: 2005-08-22

Posts: 1,504

Re: Got A question for everyone :)

This thread gave me a funny idea. What if you had a friend write you a check for pi dollars, and you try to cash it at the bank. You could perpetually refuse the banks payment and insist that they have not given you the right amount of money!

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A logarithm is just a misspelled algorithm.

Identity

Member

Registered: 2007-04-18

Posts: 934

Re: Got A question for everyone :)

How about adding an exclamation mark at the end of the amount!