[dancestar101]

I can't figure out this problem! Do I multiply or add? Same for the 2nd one!

1. Robin has read 3/4 of a book. Mark said he had read 1/2 as much as robin. What fraction of the book has mark read? (I have 2 show my work)

2. a bycicle is on sale for 2/3 of its original price . If the original price is $354, what is the sale price?

I don't need the answers but the strategies to answer them.

[YoungHyperLink]

In both cases you need to multiply.

1/2 times 3/4 will give you the fration of the book Mark has read, and 2/3 times 354/1 will give you the sale price.

Does that help?

[YoungHyperLink]

In both cases you need to multiply.

1/2 times 3/4 will give you the fration of the book Mark has read, and 2/3 times 354/1 will give you the sale price.

Does that help?

[YoungHyperLink]

Sorry, posted twice by accident.

[dancestar101]

In both cases you need to multiply.

1/2 times 3/4 will give you the fration of the book Mark has read, and 2/3 times 354/1 will give you the sale price.

Does that help?

Yes thanks so much! You saved my math grade!:):D

[YoungHyperLink]

My pleasure. As long as you are not looking for answers to your homework problems, but just for help in understanding them, remember there are lots of people willing to help here.

[donf]

Q 1) 3/4 X 1/2 = (?)
Q 2) Original Price $354 X 1/3 = (X) $354 - X = Sales price.

[morgaine300]

Except that two of you just gave out the answers without a bit of the strategy.

[YoungHyperLink]

Except that two of you just gave out the answers without a bit of the strategy.

Hmm... not the answers, exactly, but I see what you mean. I´ll try to explain the concept next time and not the procedure, if that's what you mean. Thanks.

[KISS]

There is another way of doing #2. I might confuse you. I might not.

2. a bicycle is on sale for 2/3 of its original price . If the original price is $354, what is the sale price?

On first glance it almost looks like a percentage problem.

X% of $354 is Y

That's solved by X/100 = Y/$354

Percents can be written as decimals, so instead of X/100 the equation is

2/3 of $354 is Y

When you see it that way, 2/3*$354 is the answer

or even

2/3 = Y/354 --> 2/3 * 254

also 2/3 is 2/3*100 or 66.666666... %

or 66.6666% of 254

and for #1, by inspection. 50% of 3/4
or book is 100% or 1

R read 3/4*100% or 75%
M = 1/2 * R or M = 50% of R

or M =50% of 75%

M = 1/2 * 3/4 because 50% = 1/2 and 75% = 75/100 or 3/4

[morgaine300]

Or at least the concept along with the procedure. Since the question was whether to multiply or add, saying to multiply isn't really explaining the why. (Pictures are good, but that's such a pain in the rear on here.)

[Wondergirl]

Or at least the concept along with the procedure. Since the question was whether to multiply or add, saying to multiply isn't really explaining the why. (Pictures are good, but that's such a pain in the rear on here.)

Yeah, my math teachers always said start with a picture if at all possible. And we aren't supposed to do the homework here and supply the answers.

[morgaine300]

Strange, none of my math teachers said to start with pictures. I had to figure that one out for myself. Fortunately I did, or I would've spent the rest of my life thinking I was stupid at math.

[Unknown008]

Pictures are worth 1000 words... or so it is said. I use pictures when I got stuck, it's the best way to get out. If that does not help, then, I remain stuck :o

- Why multiply?
You read the problem as "'half' of 'three quarters'". That means, you need to find 3/4 divided by two. That is the equivalent of 3/4 * 1/2, since multiplying by half is the same as dividing by two.

- Second number.
Perhaps using proportions will help?

1 (whole) -> $354
2 -> 354 * 2
1/2 -> 354 * 1/2
Etc

So, 2/3 -> 354 * 2/3