Percent of Change: Increase and Decrease math problems

Can anybody solve this and explain? 66 and 2/3%-45=

My son is struggling with this and I can't explain it because I don't understand it either.

[Edited 7/20/09 18:48pm]

66 2/3 = 65 5/3
45 = 44 3/3
_____
21 2/3

God DAMN there are a lot of dumb motherfuckers walking around! - George Carlin
Stalkerwomen of the world unite in delusion!!!!!

OR:

I convert 66 2/3 into a decimal. 2/3 = .66666 yada yada

So 66.666 minus 45 is 21.6666

God DAMN there are a lot of dumb motherfuckers walking around! - George Carlin
Stalkerwomen of the world unite in delusion!!!!!

can u explain in another way?

by the way this is Marquis.

heybaby said:

God DAMN there are a lot of dumb motherfuckers walking around! - George Carlin
Stalkerwomen of the world unite in delusion!!!!!

Is the question posted exactly as it's written in the book?

coolcat said:

Is the question posted exactly as it's written in the book?

God DAMN there are a lot of dumb motherfuckers walking around! - George Carlin
Stalkerwomen of the world unite in delusion!!!!!

Vendetta1 said:

coolcat said:

Is the question posted exactly as it's written in the book?

Yeah, I'm trying to figure out how I need to go about trying to explain the answer.

coolcat said:

God DAMN there are a lot of dumb motherfuckers walking around! - George Carlin
Stalkerwomen of the world unite in delusion!!!!!

Vendetta1 said:

heybaby said:

by the way this is Marquis.

Hi Marquis.

Do you know how to convert fractions to decimals?

Does the book provide an example?

Can you type one here?

Maybe I'll be better able to explain it if I know what the book is saying.

Since there is no trailing decimal after the "45", think of it as 66.667 - 45.000.

66.667-
45.000
-----

21.667

All you have to do is subtract 45 from 66. The .6667 is subtracting 0.000, so it just carries down.

"Guitar" on Leno is the greatest performance in the history of rock ' roll

Second Funkiest White Man in America

It sure is nice having adults running our government now

coolcat said:

"Guitar" on Leno is the greatest performance in the history of rock ' roll

Second Funkiest White Man in America

It sure is nice having adults running our government now

Vendetta1 said:

coolcat said:

I get the feeling that there should be a multiply there:

(66 and 2/3 %) x (-45)

ie: what is 66 and 2/3 % of -45...

if that's the case then:

(66 2/3)% x (-45)

= (200/3)% x (-45)

= (200/300) x (-45)

= (2/3) x (-45)

= -30

But that's only if there's that multiply there...

I was thinking that same thing!!!

heybaby said:

Vendetta1 said:

Hi Marquis.

Do you know how to convert fractions to decimals?

Does the book provide an example?

Can you type one here?

Maybe I'll be better able to explain it if I know what the book is saying.

the examples were:

Percent of Decrease: original price minus new price divided by original.

perc. of increase: new price minus original price divided by original.

coolcat said:

heybaby said:

Thanks ya'll :crazy:

Marquis has went to bed. I will show him this thread in the morning. But still keep the different ways of answering the question coming-hope he gets it. Coolcat I get yours-Sorta

Anxiety said:

coolcat said:

thekidsgirl said:

coolcat said:

Ah.... so the question is asking... take 45... subtract 66 2/3% of it... what is the result... so what you want to do is:

45 - (66 2/3 %)x45

= 45 - (200/3 %)x45

= 45 - (200/300)x45

= 45 - (2/3)x45

= 45 -30

= 15

Hope that helps.

Now you can check your answer, to make sure. Use the definition of percentage decrease... see if you get back 66 2/3 %...

that is beautiful....I love math

thekidsgirl said:

coolcat said:

Ah.... so the question is asking... take 45... subtract 66 2/3% of it... what is the result... so what you want to do is:

45 - (66 2/3 %)x45

= 45 - (200/3 %)x45

= 45 - (200/300)x45

= 45 - (2/3)x45

= 45 -30

= 15

Hope that helps.

Now you can check your answer, to make sure. Use the definition of percentage decrease... see if you get back 66 2/3 %...

that is beautiful....I love math

God DAMN there are a lot of dumb motherfuckers walking around! - George Carlin
Stalkerwomen of the world unite in delusion!!!!!

heybaby said:

Thanks ya'll :crazy:

Marquis has went to bed. I will show him this thread in the morning. But still keep the different ways of answering the question coming-hope he gets it. Coolcat I get yours-Sorta

Vendetta1 said:

thekidsgirl said:

that is beautiful....I love math

So do I.

heybaby said:

Vendetta1 said:

So do I.

I go as far as Geometry goes and thats it

heybaby said:

Vendetta1 said:

So do I.

I go as far as Geometry goes and thats it

Fractions are your friends! The question basically asked what is 2/3 off of 45. Yes, the answer is 15.

thekidsgirl said:

heybaby said:

I go as far as Geometry goes and thats it

OMG! I got to teach one of my student Geometry last school year and it was amazing going over all that again
Polygons must be like aphrodisiacs