Why would you ever need to find the Greatest Common Factor?

[cathmom]

I'm just wondering. I don't think I've ever needed to for anything I've ever done.

[gardenschooler]

Don't skimp on factoring!!! You'd regret it later.

[DawnUK]

I believe that it's helpful in higher maths. When you want to to simplify a fraction, it helps to know the greatest common factor. My oldest is just 11, so I haven't taught the higher maths yet, but that's my best guess!

 

--Dawn

[jennyt]

You should always write a fraction answer in its simplest form, and that means checking your fraction to see if the numerator and denominator have a greatest common factor larger than 1 and then divide them both by that factor. Invaluable skill for fractions!

[cathmom]

Thanks.

 

Ok, simplifying fractions, I knew there was something. Not that I have ever simplified a fraction in my every day life.

 

And for factoring polynomials and all that, well, I haven't done that either LOL. Not that I was going to skimp on it - it was just something I was thinking about. So much of math seems to have no practical application whatsoever, no wonder people hate it.

[Ali in OR]

So much of math seems to have no practical application whatsoever, no wonder people hate it.

 

Aack! Don't say that! You are training the brain to think logically and to be nimble and quick. And I do use fractions regularly. Maybe other people don't regularly multiply recipes by 2/3 or 1/2 or 1 1/2, but if you have the ability to make those calculations easily, you can cook just the right amount of food for your family. Even skills that don't get used much beyond the math classroom such as factoring polynomials still train the brain to think in a particular way. Not to mention all of the doors that are opened career-wise to people who are comfortable with mathematical ideas and are proficient skill-wise.

[Kim in SouthGa]

if someone shows up for a party with one cake that is half choc. and half white, and someone else shows up with a cake that is 1/3 choc., 1/3 white, and 1/3 yellow. I want to make sure I get all the chocolate I am due.;)

 

Seriously, I have used it in cooking, say when I want to half a recipe that uses 2/3 cup or something like that.

[Peela]

Lol, that's how I feel about most maths past about 7th or 8th grade! I cant see why most kids are made to learn so much that they will never use for the rest of their lives. At least here in Australia, I dont know about over there, they have pushed all this university level maths down into highschool. I just dont get it and I am not sure I want to kowtow to it, either! I am having a maths rebel moment.

There, I needed to say that. thanks.

[cathmom]

Aack! Don't say that! You are training the brain to think logically and to be nimble and quick. And I do use fractions regularly. Maybe other people don't regularly multiply recipes by 2/3 or 1/2 or 1 1/2, but if you have the ability to make those calculations easily, you can cook just the right amount of food for your family. Even skills that don't get used much beyond the math classroom such as factoring polynomials still train the brain to think in a particular way. Not to mention all of the doors that are opened career-wise to people who are comfortable with mathematical ideas and are proficient skill-wise.

 

I use fractions and change recipes all the time. What I don't do is sit down and figure out the GCF of 24 and 30. I just want to clarify that I am not math-phobic myself! But so far, none of my dc like math and my younger dd absolutely detests it! I have been thinking about the way math is taught for years, and my recent thread on here about what subjects you never got in school only confirms that the way math is taught in school is not good, so why should homeschoolers emulate it? You can read my reflections if you are interested in this blog post: http://www.homeschoolblogger.com/cathmom/477749/

 

The other thing I see in people and my daughters is that when math is practical, they get it. My math-phobic, math-hating daughter can double recipes or cut them in half or whatever with ease. She handles money just fine. The way math is taught it is just so divorced from any reason why you would use it in your life.

 

I have been reading the book Made to Stick and it discusses an accounting class that was taught like a story. Some friends start a business and ask you to help them with accounting. The students then learn all the fundamentals of accounting by going through the story of the start-up business. "After experiencing the case study, students with high GPAs were more likely to major in accounting. The concreteness actually made the most capable students want to become accountants...In the next accounting course - taken an average of 2 years later - the first section...built heavily on the concepts ...learned in introductory accounting. Students who had worked through the case study scored noticeably higher on this first exam...C average students scored 12 points higher...Concreteness sticks." But math is hardly ever taught concretely. I think this approach could really help my daughters and so I am looking for resources that do that.

 

Thanks everyone for your input!

[Melissa in Australia]

Lol, that's how I feel about most maths past about 7th or 8th grade! I cant see why most kids are made to learn so much that they will never use for the rest of their lives. At least here in Australia, I dont know about over there, they have pushed all this university level maths down into highschool. I just dont get it and I am not sure I want to kowtow to it, either! I am having a maths rebel moment.

There, I needed to say that. thanks.

 

what university level math?? I am using an American program, (Saxon) will my children not have enough math? should I switch to an Australian math program?

I have only looked at Australian programs up to year 8 and thought they were about equal to Saxon.

Peela, you have me worried now.

[jennyt]

I love maths and my dds so far seem to be enjoying it quite a lot but I have been really shopping around with math topics. My dds do Horizon maths in the afternoon but in the mornings, I try to make it as practical as possible. We've had the whole room set up as a coffee shop (and worked out how to set it up and take it down again as quickly as possible - we don't spend the whole morning doing math), I've had floor mats as number tracks, huge lengths of paper for dividing fractions into smaller fractions, and for basic addition, subtraction, multiplication and division, I've come across 2 books called "Teaching Number Facts using a Number Sense Approach" by James Burnett and he tries to start with practical applications and finish up with puzzles and games and use a lot of manipulatives in between. I'm an ex-highschool math teacher and I want my dcs to love math and to appreciate it as well. And ... I don't want to cycle around and have to reteach topics over and over again - hence my choice of Horizons in the afternoon.

 

HTH,

 

Jenny

[Peela]

what university level math?? I am using an American program, (Saxon) will my children not have enough math? should I switch to an Australian math program?

I have only looked at Australian programs up to year 8 and thought they were about equal to Saxon.

Peela, you have me worried now.

 

Melissa I am no expert. I am using Haesse and Harris, a S.A. program with an excellent reputation (I am in W.A.). My daughter's Year 9 book is so full of things I never had to learn and she is getting beyond where I can help her. It is really challenging, and I actualy remember highschool maths and came top of the year in year 11. I never liked maths but I am not math phobic. I just can't see the use of much of those higher years, for most students.

But its difficult to compare Aussie and U.S. programs, particularly Saxon, because they have a different way of teaching. Australian programs tend to teach one topic at a time and keep coming back to it and deepening the understanding of it, year after year. My friend uses Saxon, her dd is the same age as mine- some stuff my daughter is doing (they are year 9) her friend hasn't done- yet her friend's Saxon Algebra 1 covers up to some year 10 algebra.

I wouldnt worry about it up to mid highschool- but then have a look at the Aussie programs if your child is headed to a science or maths needed career, as they are of high standard, and there may be differences that become significant with exams etc It may not be a problem, but as far as I have seen, Australian kids scored pretty high on international tests i saw a few years back, and U.S. kids didnt- dont know what programs they were using, but I don't have a problem using Australian maths programs. Of course, Saxon has a difference in the way it is taught and works for many kids- I dont for a minute think its a bad program.

[Melissa in Australia]

thank you peela .

food for thought.

[Penny]

Well, just because we as homeschool moms don't pull out our calculus everyday doesn't mean that math isn't useful!

 

In my former engineer life (ChE) I used my higher level math everyday. Now there is a shortage of engineers because American kids aren't being educated in math. Engineering is just one career where math is a must. There are many others. Unless you want to choose for your child a non math career, just go ahead and follow the program regardless of if you understand 'why' or not. For example, I don't understand the full progression of language arts. So, I just do what SWB says (with research and study of course) because she obviously does understand. Until I absolutely know better, I'm not going to rob them of a good language arts education just because I don't use these skills in my life.

 

However, I do believe that one of the problems with math in America (and it looks like Australia too) is the pushing down of higher level concepts when the earlier concepts haven't been mastered. I'm guilty of wanting my kids to prove themselves when it comes to school (call this PRIDE) and therefore trying to teach them more than they are ready for. So, I do not do an advanced math program with my kids. We do R&S which is a year behind Horizons, and some behind Abeka. I think it prepares the students better by taking it slower and absolutely mastering the basics.

 

BTW, I also had that question about GCF (and about LCM) because I didn't remember learning it. However, I realized that because of experience with fractions, I automatically used GCF without realizing it. Now my kids have to learn GCF just to get the same experience. It's good to keep asking those questions and just keep plugging through!

 

Penny

[Reya]

Lol, that's how I feel about most maths past about 7th or 8th grade! I cant see why most kids are made to learn so much that they will never use for the rest of their lives. At least here in Australia, I dont know about over there, they have pushed all this university level maths down into highschool. I just dont get it and I am not sure I want to kowtow to it, either! I am having a maths rebel moment.

There, I needed to say that. thanks.

 

 

If you understand the math, you WILL use it as an adult. People don't use it only because they never understood it. Yes, I have used calculus in my daily life.