View entire discussion
[<< prev] [ next >>]
From: Loyd To: Teacher2Teacher Public Discussion Date: 2004022218:31:33 Subject: Re: Re: Re: Re: you can ALWAYS divide across! On 2004022216:06:20, Linda wrote: >This is the answer I am looking for for my sixth graders that have no >trouble finding common denominators for addition and subtraction, but >can't cope with 3 different methods of doing 4 different >operations...add, subt, div, and mult! I use the partitive model to >show why and how we use common denominators. It just makes sense to >teach them division in the same way. The meaning does not get lost1 >Thank you for the tip! > > The inverting method is very simple and does not cause near as much problems as subtracting a mixed number from a whole number. In complex fractions we could have something like this: 1 -- 3 ---- 1 -- 4 Multiplying the numerator and denominator by the reciprocal which is 4/1 results in a simple fraction 1/3 x 4/1. That makes it easy. Why confuse things by finding the LCD which is not necessary. I have tutored lots of college students and high school students and lots of them have great problems solving simple fractions. I don't see why teaching another method will help students learn math better. They will become confused again when their college professor uses the older method unless they are really good at math. A new method, just makes parents who are trying to help their students, complain about what they call the new math. If you are going to show them your LCD extra step method, then you should show them both methods. Remember, it is the theory that counts, not the answer. If you just want the answer, get one of the new calculators with a fraction button.
Math Forum Home || The Math Library || Quick Reference || Math Forum Search