#### Comment Preferences

• ##### Upper class HS math students(4.00)
can't subtract or divide mixed fractions at all.  They are totally clueless.

Unfortunately, our calculator society has taken away a lot of common sense math knowledge.

I taught Algebra for six weeks this last fall and tried to tell my students to do the least amount of math possible.  If you can reduce fractions, do it first, don't multiply 6*8 then divide by 4*2.  I think they are so used to using their calculators that the process of looking at a problem and figuring out the best way to solve it is moot.

America works best in spreading democracy when people over the world see something they want to emulate. Richard

[ Parent ]

• ##### Having taught college math...(none)
...and being an algebraist, I would be remiss if I didn't point out that working with mixed numbers is the skill that is least important of all the skills learned in mathematics.  In my ideal world, they would be banished.  In particular, learning to do division of mixed numbers in elementary or middle school is counterproductive to learning algebra.  If one wants to divide 3 1/3 by 1 3/4, one should begin by multiplying each by 12, using the distributive law to get 36 + 4 = 40 for the first number and 12 + 9 = 21 for the second.  The answer is 40/21.  Reduce if necessary, but leave it as a fraction, damnit. ;-)

Robyn

Teacher's Lounge opens each Saturday, sometime between 10am and 11am EST

[ Parent ]

• ##### But in the "real world" it is important(4.00)
Carpenters and people on the shop floor work in mixed fractions all the time.  I work part time at my brothers shop and he sells parts that are in measured in fractions of inches.  It becomes very important in these applications to be able to do basic math with mixed fractions.

Upper level mathematicians will write 3 1/2 as 7/2, but that doesn't happen in catalogs for the manufacturing industry.  There is a disconnect between what algebraists use for math and what the carpenter needs.  He needs to know if he has a piece of lumber that is 8 feet 3 1/2 inches long and he needs a piece that is 2 feet 4 3/4 inches long, how many pieces can he get.  He will NEVER leave results in an improper fraction form.

Yes, as someone who loves algebra and actually likes doing these types of problems, I understand the 'offical' way, but having grown up in manufacturing world, I also know there is a need for understanding the requirements of the person in the world outside of academia.

America works best in spreading democracy when people over the world see something they want to emulate. Richard

[ Parent ]

• ##### I actually expected this response...(4.00)
...since my dad was an electrician. ;-)

I recognize the fact that since they are used in so many instances, that they can't be ignored.  I just rue the day they were invented.  If you track back students to where they started having troubles in mathematics, you generally find one of two places:  long division or mixed numbers.  Lack of success handling these leads to disinterest, which gets reinforced by the fact that it's perfectly fine in this society to say, "I was never any good at math."

Robyn

Teacher's Lounge opens each Saturday, sometime between 10am and 11am EST

[ Parent ]

• ##### I hate that it's ok to be bad in math(4.00)
but unacceptable to be illiterate.

I actually think that students would be much better in fractions if they did more of home economics tpe activities in school again.  If you cook or build something and have to up or down scale it, you learn the skill pretty fast.  If you read a useless story problem in a book that the student doesn't care about, they won't bother to worry about learning, because they will assume that it won't impact their lives.

"Life is a story problem"

America works best in spreading democracy when people over the world see something they want to emulate. Richard

[ Parent ]

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