Jump to content


Photo

The Maths Thread

For Hopeless Cases!

  • Please log in to reply
368 replies to this topic

#1 Misterioso

Misterioso

    Virtuoso

  • Members
  • PipPipPipPipPip
  • 5507 posts
  • Member: 13351
    Joined: 18-July 07
  • Outer Hebrides

Posted 10 March 2014 - 20:57

I know there are at least two of us in need of this thread!  We can compare knowledge, check answers, and ask questions in the hope that the odd maths buff might look in occasionally to impart to us his wisdom!

 

Tonight I have learnt about scientific notation and can (usually successfully!) convert it into decimals and back again!  :woot:

 

But (puzzled) is expressing something as whatever x 10 to the power of whatever the same as Standard Form?  I was supposed to learn learnt this at school, and it seemed much more tricky!  :blink:


  • 0

#2 Norway

Norway

    Virtuoso

  • Members
  • PipPipPipPipPip
  • 4304 posts
  • Member: 452922
    Joined: 05-May 12

Posted 10 March 2014 - 21:00

Oh my you've lost me already! Can't we play with coloured blocks in the sand pit to start with?


  • 2

#3 Maizie

Maizie

    Virtuoso

  • Members
  • PipPipPipPipPip
  • 6502 posts
  • Member: 9360
    Joined: 05-February 07
  • Bishop's Stortford, Hertfordshire

Posted 10 March 2014 - 21:01

Certainly when I was at school, scientific notation and standard form were synonyms :)

I think you'll hear it called scientific notation these days.


  • 0

#4 BadStrad

BadStrad

    Virtuoso

  • Members
  • PipPipPipPipPip
  • 3742 posts
  • Member: 88756
    Joined: 28-January 10

Posted 10 March 2014 - 21:05

Almost the same. For standard form the number you times by the power of ten must be 1 or above, but less than 10. So 1 * 10^2 is standard form, as is 9.999999999 *10^2, but 0.9 *10^2 is not, neither is 45 * 10^4.
  • 0

#5 BadStrad

BadStrad

    Virtuoso

  • Members
  • PipPipPipPipPip
  • 3742 posts
  • Member: 88756
    Joined: 28-January 10

Posted 10 March 2014 - 21:06

Almost the same. For standard form the number you times by the power of ten must be 1 or above, but less than 10. So 1 * 10^2 is standard form, as is 9.999999999 *10^2, but 0.9 *10^2 is not, neither is 45 * 10^4.
  • 0

#6 Misterioso

Misterioso

    Virtuoso

  • Members
  • PipPipPipPipPip
  • 5507 posts
  • Member: 13351
    Joined: 18-July 07
  • Outer Hebrides

Posted 10 March 2014 - 21:20

Oh my you've lost me already! Can't we play with coloured blocks in the sand pit to start with?

 

Don't worry, Norway, this is only day 3 in my quest to become a mathematician bit less hopeless at maths!  It really is quite a basic book I'm working from, and takes you through in bite-size digestible chunks so that you actually end up thinking you can do what you thought you were utterly incapable of!

 

Almost the same. For standard form the number you times by the power of ten must be 1 or above, but less than 10. So 1 * 10^2 is standard form, as is 9.999999999 *10^2, but 0.9 *10^2 is not, neither is 45 * 10^4.

 

Um.....did anyone understand that?  :blink:  :blink:  :blink:

 

BadStrad, I'm not sure what the asterisks mean - nor those odd side-on accents......  Remember, we are Hopeless Cases!!  :)  

 

Edit: just looking at that again, doesn't scientific notation also have to be a number between 0 and 10?  Confused.   :(


  • 0

#7 corenfa

corenfa

    Virtuoso

  • Members
  • PipPipPipPipPip
  • 5945 posts
  • Member: 95861
    Joined: 28-March 10
  • Here

Posted 10 March 2014 - 22:20

I found https://www.khanacademy.org/ invaluable when I had to revise a lot of maths for my current job. Though what I needed was A-level, this site does things from US 3rd grade (I think it corresponds to 3rd year of school here?). It is a US site so the grades are US school grades, but I'm sure there is a correspondence, and the classes are listed by topic. 

 

What I like about it is how it is presented in bite size sessions of up to 20 minutes. It's just one guy and a notepad-like application so he talks and writes at the same time. Some people like that style, some don't - I wondered how I would take to it but after watching a few, it definitely worked for me. Much better than any other online course format. 


  • 0

#8 BadStrad

BadStrad

    Virtuoso

  • Members
  • PipPipPipPipPip
  • 3742 posts
  • Member: 88756
    Joined: 28-January 10

Posted 10 March 2014 - 22:26

The asterisk is the same as x (times). The little hat is the symbol for 'raise to the power of' the number after it. So 3^2 is the same as 3 x 3 ie 9.

2*10^2 is 2 x 10 x 10 ie 200.

Sorry the astrisks and hats were habit from the days when word processors couldn't do maths' symbols.

To answer the other part, no 9.9999999... is the max in standard form as to get 10 you'd use 1 x 10^1 (1 x ten to the power 1 - a number to the power 1 is the number itself).
  • 0

#9 BadStrad

BadStrad

    Virtuoso

  • Members
  • PipPipPipPipPip
  • 3742 posts
  • Member: 88756
    Joined: 28-January 10

Posted 10 March 2014 - 22:31

If you search for 'maths enhancement project' the first hit should be to Plymouth uni. There are excellent pdfs on the site for those who like to read instead of watch videos. They go from KS1 to A level (A2) UK syllabus.
  • 0

#10 mel2

mel2

    Virtuoso

  • Members
  • PipPipPipPipPip
  • 4528 posts
  • Member: 6928
    Joined: 15-May 06
  • East Yorkshire

Posted 10 March 2014 - 22:47

Oh dear.
Why do we times anything by something to the power of 10 anyway?


( thick, thick, thickety-thick....)
  • 1

#11 Tenor Viol

Tenor Viol

    Virtuoso

  • Members
  • PipPipPipPipPip
  • 5944 posts
  • Member: 343214
    Joined: 25-October 11
  • North Shropshire

Posted 10 March 2014 - 23:28

Couple of things...

 

Generally, unless you're in the weird world of IT like me, we usually count in "Base 10". That is, we count things in 10s: we go from 0 to 9 in the 'units' column. When we get to ten, we put a '1' in the tens column and a zero in the units column: 10.

 

The term 'raise to the power of' means to multiply it by that number the number of power times. If you had 2 cubed: 23 that means raise two to its third power, which is the same as 2 x 2 x 2 = 8.

 

Because we generally use Base 10, we express things in terms of Base 10. So, to present 124 in 'scientific notation' we write 1.24 x 102 meaning 1.24 x 10x10, i.e. 1.24 x 100, 10 raised to its second power. It is customary to write the number as m.nn... x10p in our example, we could write 12.4 x 101 which is 12.4 x 10.

 

In the world of IT, we use binary arithmetic - Base 2 (1 = 1, 2 = 10, 3 = 11 etc) or hexadecimal - Base 16 (9 = 9, 10 = A.... 15 = F, 16 = 10) :unsure: 


  • 0

#12 DaisyChain

DaisyChain

    Advanced Member

  • Members
  • PipPipPip
  • 873 posts
  • Member: 380975
    Joined: 01-January 12
  • Kent

Posted 10 March 2014 - 23:36

:hides:  :peace2:


  • 2

#13 Violin Hero

Violin Hero

    Virtuoso

  • Members
  • PipPipPipPipPip
  • 3608 posts
  • Member: 26561
    Joined: 08-March 08
  • South London

Posted 10 March 2014 - 23:53

In the world of IT, we use binary arithmetic - Base 2 (1 = 1, 2 = 10, 3 = 11 etc) or hexadecimal - Base 16 (9 = 9, 10 = A.... 15 = F, 16 = 10) :unsure: 

 I work in IT and understand binary but certainly not hexadecimal. I know IPv6 is in hexadecimal and dread the day we all start using them on corporate networks!

 

However back on topic and I must say I was very lazy at maths and got a C grade GCSE, with a prediction of A, and can only just remember all the stuff  here even though I only did my GCSEs 7 years ago!


  • 0

#14 Tenor Viol

Tenor Viol

    Virtuoso

  • Members
  • PipPipPipPipPip
  • 5944 posts
  • Member: 343214
    Joined: 25-October 11
  • North Shropshire

Posted 11 March 2014 - 00:33

OFFTOPIC: Hex is used as a shorthand way of representing large binary numbers as one hex digit represents a binary half-word of 4 binary digits: binary 1111 = 15 = hex F 

 

Back to topic


  • 0

#15 BadStrad

BadStrad

    Virtuoso

  • Members
  • PipPipPipPipPip
  • 3742 posts
  • Member: 88756
    Joined: 28-January 10

Posted 11 March 2014 - 00:39

Mel2 we use standard form to represent big numbers like distances in the solar system, or tiny numbers like within atoms. It saves having lots of zeroes.
  • 0