Fractions. Help sought please.

[mcshroom]

That works. If you are facing the wrong way (-ve) but walking backwards(-ve) then you are moving in the same direction as if you were facing forwards (+ve) and walking forwards (+ve).

If you were facing the right way (+ve) but walking backwards (-ve), or facing backwards (-ve) but walking forwards (+ve) you would in both cases be walking the wrong way (-ve)

 

[Fnaar]

That works. If you are facing the wrong way (-ve) but walking backwards(-ve) then you are moving in the same direction as if you were facing forwards (+ve) and walking forwards (+ve).

If you were facing the right way (+ve) but walking backwards (-ve), or facing backwards (-ve) but walking forwards (+ve) you would in both cases be walking the wrong way (-ve)

That's like playing all the right notes, but in the wrong order (insert Morecambe and Wise/Andre Preview clip here ... )

 

[benb]

I never had to use any of the maths in my work apart from a bit of Ohm's law

I had a handy shortcut for this (and works for any similarly structured equation)
Ohm's law is V=IR (Voltage through a circuit is equal to current multiplied by resistance)

Imagine a triangle with V at the top, I on the bottom left, and R on the bottom right. Cover up the missing element you need to work out, and the remaining elements will already be in the right places for the calculation.

So cover up I, and you know immediately that to calculate it you need to divide Voltage by resistance.
Cover up R and you need to divide Voltage by Current to get it.

 

[twentysix by twentyfive]

For those who don't know, my maths are poor. My formal education ended when I was about 13 years old and I never did maths anyway at my school. I have recently enrolled on a GCSE course just for the challenge of it, but I have so far to go it's frightening!

Well done Compo. It isn't frightening really. Just take a step at a time and consolidate what you have learned before moving on to the next thing. Lots of practice doing the "homework" hammers it home. You are my hero - well done indeed.

 

[twentysix by twentyfive]

Just remember that, although theoretically, it can be done in reality it can't. If you have 1/2 an apple in your hand and you cut 3/4 of an apple off it this equals a trip to the hospital! Apart from that good on ya for accepting that you don't know but have the courage to find out.

Well it is real - the electric charges on quarks and anti-quarks are -1/3 and -2/3 in units of the proton charge. There's almost certainly other real examples - I just can't think of them at the moment.

Reality can be quite strange

 

[postman]

A VERY BIG WELL DONE.From me here at 23 or is it 22 or it could be 21.Keep it up.

 

[ArDee]

Volume of a sphere = 4/3πr[sup]3[/sup]

or 8/3πr[sup]3[/sup] = the volume of 2 spheres

 

[byegad]

For those who don't know, my maths are poor. My formal education ended when I was about 13 years old and I never did maths anyway at my school. I have recently enrolled on a GCSE course just for the challenge of it, but I have so far to go it's frightening!

It's something anyone can learn with the right teaching, but there are limits to how far most people can get with harder sums (aka Further Maths). The good news is that that limit is well past GCSE level. I admire your courage and persistence.

 

[Cheddar George]

or 8/3πr[sup]3[/sup] = the volume of 2 spheres

Sounds like balls to me.

 

[ColinJ]

Well it is real - the electric charges on quarks and anti-quarks are -1/3 and -2/3 in units of the proton charge. There's almost certainly other real examples - I just can't think of them at the moment.

Reality can be quite strange

Money? You start off with £50,000 and you want to buy a house costing £250,000. You get a mortgage from a bank for £200,000 and buy the house. Your account now shows -£200,000!

 

[Deleted member 26715]

Money? You start off with £50,000 and you want to buy a house costing £250,000. You get a mortgage from a bank for £200,000 and buy the house. Your account now shows -£200,000!

You then pay it back over 25 years at £2000 per month i.e. £24,000 per year times 25 years means you've paid £650,000 for a £250,000 house

Alan...

 

[ColinJ]

You then pay it back over 25 years at £2000 per month i.e. £24,000 per year times 25 years means you've paid £650,000 for a £250,000 house

Alan...

Banks - pah!

(Don't get me started on Wonga!)

 

[thom]

[QUOTE 2722065, member: 9609"]On the subject of negative numbers, I have never been able to get my head round the following, I know the rule but don't know the logic behind it

(+3) * (+3) = (+9)
(-3) * (+3) = (-9)
(-3) * (-3) = (+9)

Why does multiplying two negative numbers get a positive?
[/quote]

Without spending much time to go into it, algebra tells us it has to be so (if you accept that x*y = y*x):

( x * x ) - ( y * y ) = ( x + y ) * ( x - y )

So if y = -x, then x + y = 0 and the right hand side = 0. We are then left with

( x*x ) - ( (-x)*(-x) ) = 0

or equivalently:

x * x = (-x) * (-x)

QED innit

 

[twentysix by twentyfive]

Money? You start off with £50,000 and you want to buy a house costing £250,000. You get a mortgage from a bank for £200,000 and buy the house. Your account now shows -£200,000!

Just attempting the reality of negative fractions as the OP was interested in such.

No worries tho' I'm always minus some dosh

 

[ColinJ]

Just attempting the reality of negative fractions as the OP was interested in such.

No worries tho' I'm always minus some dosh

Tell me about it!

No, I don't mean actually tell me about it ... I mean I have a minus sign on my bank statement too!