tammyw Posted January 29, 2014 Share Posted January 29, 2014 I'm having a hard time coming up with real world examples of when we would convert a fraction to a decimal. I think it's a great question, but I'm completely blank right now and a google search only tells me "how" to convert, which we already know! Quote Link to comment Share on other sites More sharing options...
wapiti Posted January 29, 2014 Share Posted January 29, 2014 money percent scientific notation Quote Link to comment Share on other sites More sharing options...
tammyw Posted January 29, 2014 Author Share Posted January 29, 2014 money percent scientific notation Yep, that makes sense! Why couldn't my brain figure this out on its own?! Quote Link to comment Share on other sites More sharing options...
Tmhearn Posted January 29, 2014 Share Posted January 29, 2014 Cooking/Kitchen Prep Add .25 ounces of vodka to 4.5 ounces of orange juice to make the perfect screwdriver. ;-) Quote Link to comment Share on other sites More sharing options...
mathmarm Posted January 29, 2014 Share Posted January 29, 2014 Fractions are simply another representation of decimals, hence many sources refer to them by their full-name, or sorts : DECIMAL fractions. We use them in cooking, measuring, money, precise time (usually sporting events and scientific experiments where fractions of seconds mean ALOT), scientific notation and as an extension of our understanding of place value. Quote Link to comment Share on other sites More sharing options...
SKL Posted January 29, 2014 Share Posted January 29, 2014 So you can use a calculator or computer to perform further analysis. So you can perform operations more efficiently.... Quote Link to comment Share on other sites More sharing options...
thewaka Posted January 29, 2014 Share Posted January 29, 2014 So you can use a calculator or computer to perform further analysis. So you can perform operations more efficiently.... Calculators don't typically allow entering a fraction. Quote Link to comment Share on other sites More sharing options...
SebastianCat Posted January 29, 2014 Share Posted January 29, 2014 I see lots of application in cooking...... Digital scales only display decimals. But measuring cups and spoons use fractions. If I have to adjust a recipe because of a digital weight (such as 1.75 pounds of ground beef) when the recipe calls for 1 pound, by how much should I adjust the amount of ______ sauce or _______ spice if the recipe calls for 1/2 cup or 1/2 teaspoon? How about road signs? The sign says, "Exit 20, 1 1/4 mile." How much will that show on my odometer (in decimals)? Quote Link to comment Share on other sites More sharing options...
tammyw Posted January 29, 2014 Author Share Posted January 29, 2014 This is all so helpful!! Sometimes I'm really bad at thinking through the real world examples! Thanks to everyone! Quote Link to comment Share on other sites More sharing options...
My3girls Posted January 29, 2014 Share Posted January 29, 2014 Sales! Everything 1/2 Off! Lol Quote Link to comment Share on other sites More sharing options...
fdrinca Posted January 29, 2014 Share Posted January 29, 2014 time (1/2 of a hour) I used to do the time cards for my high school job at a dry cleaners. It was the first time I realized what math illiteracy was. I was tasked with training another employee to do the job when I left for college. I couldn't make her believe me that 30 minutes did not equal 0.30 hours. Quote Link to comment Share on other sites More sharing options...
Incognito Posted January 29, 2014 Share Posted January 29, 2014 Easy way to add fractions with different denominators Quote Link to comment Share on other sites More sharing options...
Dana Posted January 30, 2014 Share Posted January 30, 2014 Easy way to add fractions with different denominators Only if decimals terminate. It would be awful for 1/7 + 2/3. Fractions are typically better mathematically than decimals. They're more exact. Rational numbers are defined as the ratio of two integers...as fractions. Irrational numbers are those whose decimal representation never repeats and never ends. Get good at fractions and in fractional forms. Be able to work with decimals for when approximations are needed. Quote Link to comment Share on other sites More sharing options...
Amy in NH Posted January 30, 2014 Share Posted January 30, 2014 Because it is easier to compare and manipulate them. Quote Link to comment Share on other sites More sharing options...
WishboneDawn Posted January 30, 2014 Share Posted January 30, 2014 Precision.. 22/7 is an approximation and only gets you so far. Converting it to 3.14.... allows for increasing precision. Quote Link to comment Share on other sites More sharing options...
Dana Posted January 30, 2014 Share Posted January 30, 2014 Precision.. 22/7 is an approximation and only gets you so far. Converting it to 3.14.... allows for increasing precision. No, it doesn't. If you're talking about pi, it's an irrational number. The decimal representation NEVER repeats or ends. 22/7 is a couple places more accurate than 3.14 but it is still an approximation. An exact answer includes the irrational number...like 3 pi or 5 on the cube root of two. You would use decimal approximations for irrational numbers, but it has nothing to do with fractions. Quote Link to comment Share on other sites More sharing options...
regentrude Posted January 30, 2014 Share Posted January 30, 2014 Precision.. 22/7 is an approximation and only gets you so far. Converting it to 3.14.... allows for increasing precision. This is incorrect, and I suspect you are mixing up two things. 22/7 is an approximation for pi - but 22/7 itself is an exact number for which any decimal can only be an approximation. 3.14... is also an approximation for pi. It is not exact for pi and it will never be, no matter how many digits you take along. If you want precision for pi in a math answer, the only way is to leave it symbolically as pi. A good math curriculum will teach the student to do just that. But none of this has anything to do with a preference of fractions over decimals. Quote Link to comment Share on other sites More sharing options...
Rebel Yell Posted January 30, 2014 Share Posted January 30, 2014 GRADES! 17 correct out of 20 on a test is 85%, or a B. Easy. But what about 37 out of 48? Quote Link to comment Share on other sites More sharing options...
Targhee Posted January 31, 2014 Share Posted January 31, 2014 In science you will see this a lot, especially in chemistry. The fractions, often ratios, are converted to decimals because the decimals are easier to note and work with in scientific notation. You would also use this a lot in statistics. Also, those irrational numbers cannot be expressed as a fraction and need to be worked on as a decimal (pi for example) Quote Link to comment Share on other sites More sharing options...
kiwik Posted January 31, 2014 Share Posted January 31, 2014 I prefer fractions for repeating decimals. My calculator could take fraction inputs. Quote Link to comment Share on other sites More sharing options...
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