Why Divide Fractions?
Date: Sat, 5 Nov 94 17:33:44 PST From: James Oliver Subject: Dividing Fractions Ok Doc, explain this so a random abstract counsellor (Cdn Spelling) type can understand. Where, in this wide world of ours, would one divide fractions. For example: 3 2/5 / 7/8. Can you give me a real life example. Take care James Oliver Admin for: District Area Counsellor Chetwynd Connection School District #59 (Peace River South) First Class BBS Chetwynd, BC Data 604 788-3918
From: Dr. Ken Date: Mon, 7 Nov 1994 11:41:35 -0500 (EST) James! Well, if your real life is like mine, and you're a math major, they arise all the time! But let's say you're not a math major, just a regular old citizen. Sure, they come up. Let's say you have three quarters of a pizza and four people walk in to your room and say, "hey, can I have two fifths of a pizza?" You either freak out and say "no!", or you divide 3/4 by 2/5 and see if it's bigger than four. So you get 3/4 3 x 5 15 ___ = _____ = __ = 1 7/8 2/5 4 x 2 8 So there isn't enough pizza for all four people to get as much as they want. Another example: Let's say you have 5/3 acres (or 1 2/3 acres) of land in the country, and zoning requirements are such that you have to have at least one-third of an acre to put a septic tank in. How many subplots can you divide your land into to satisfy the requirement? -Ken "Dr." Math X-Sender: email@example.com (Stephen Weimar) Date: Tue, 8 Nov 1994 09:54:44 -0500 James, I also find as I'm doing carpentry and construction that there many times when I want to evenly space several objects along a length with non-integer dimensions or figure out how many of a fractional something I can cut out of a non-integer piece of lumber. There are many ways to get close enough, but sometimes it helps to know how to get a better answer. -- steve
Date: Wed, 9 Nov 94 14:42:03 PST From: James Oliver Subject: Re: Dividing Fractions >Let's say you have three quarters of a pizza... Hi Ken, Good example, I think I'll share that with my grade 6-7 students when I am wandering through their room. Never had trouble dividing fractions but never had a firm grasp on what was happening. Take care James Oliver Admin for: District Area Counsellor Chetwynd Connection
Search the Dr. Math Library:
Ask Dr. MathTM
© 1994- The Math Forum at NCTM. All rights reserved.