Timeline for How to explain the flipping of division by a fraction?
Current License: CC BY-SA 4.0
20 events
| when toggle format | what | by | license | comment | |
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| Oct 11, 2021 at 12:37 | comment | added | Adam Rubinson | "Again most students (at this age level) will answer "18" almost immediately". I wish this were true... | |
| Jul 18, 2021 at 17:14 | comment | added | athos | After some try and error I found now he can get it by $\frac{a}{b} \div \frac{c}{d} = \frac{ad}{bd} \div \frac{bc}{bd} = \frac{ad}{bc} = \frac{a}{b} \times \frac{d}{c}$, ie he would remember the rule of flipping, but convince himself it's correct by reduction of fractions to a common denominator. | |
| Jul 18, 2021 at 17:14 | comment | added | athos | @mweiss First thank you very much sharing the approach. Indeed I taught my kid so. That was about one and half years ago. Just a trivial thing to feedback, as I fancy you might be interested. Now my kid is more comfortable manipulating expressions of numbers and variables, he still sometimes forgets the $\frac{a}{b} \div \frac{c}{d} = \frac{ac}{bd}$ rule. | |
| Jan 18, 2019 at 19:12 | comment | added | Steven Gubkin | @RustyCore Sorry. Sarcasm is often hard to convey over the internet (especially where many people DO have the view that Common Core is wrong). | |
| Jan 18, 2019 at 18:08 | comment | added | Rusty Core | @StevenGubkin I was being sarcastic. Although lots of people think that Common Core is wrong and evil. | |
| Jan 18, 2019 at 13:01 | comment | added | Steven Gubkin | @RustyCore I would be interested to have a conversation with you about Common Core, because I think that the standards are excellent. I am inviting you to chat! | |
| Jan 18, 2019 at 6:05 | comment | added | Rusty Core | @StevenGubkin Because Common Core is wrong and evil, and cannot do anything right. | |
| Jan 18, 2019 at 1:36 | comment | added | Steven Gubkin | @RustyCore What is ironic about the common core spelling out that $\frac{6}{10}$ does mean six tenths? Would you rather it be defined as $6 \div 10$ or something? | |
| Jan 17, 2019 at 17:54 | comment | added | Rusty Core | One may find it ironic that the "essential idea" that $\frac{6}{10}$ is $\frac{1}{10}$ of $6$ is clearly spelled out in the dreaded, awful, developmentally-inappropriate Common Core document. Um, I take it back. They say that $\frac{6}{10}$ is $6$ of $\frac{1}{10}$ which is even easier. | |
| S Jan 13, 2019 at 23:52 | history | edited | mweiss | CC BY-SA 4.0 |
deleted 87 characters in body
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| S Jan 13, 2019 at 23:52 | history | suggested | Fabrick2020 | CC BY-SA 4.0 |
I couldn't understand that "Suppose you want to measure six cups of flour, and all you have is a 1/2 cup scoop. How many scoops do you need?"
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| Jan 13, 2019 at 21:00 | review | Suggested edits | |||
| S Jan 13, 2019 at 23:52 | |||||
| Nov 28, 2017 at 23:35 | comment | added | WeCanLearnAnything | Here is a JUMP Math video that shows this approach. I wonder if OP got his numbers or ideas from this video... youtube.com/watch?v=e1gcBP2TmPk | |
| S Nov 1, 2017 at 13:33 | history | edited | Dag Oskar Madsen | CC BY-SA 3.0 |
Corrected "flipped" fraction
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| S Nov 1, 2017 at 13:33 | history | suggested | CommunityBot | CC BY-SA 3.0 |
Corrected "flipped" fraction
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| Nov 1, 2017 at 11:12 | review | Suggested edits | |||
| S Nov 1, 2017 at 13:33 | |||||
| Sep 20, 2016 at 0:03 | history | edited | mweiss | CC BY-SA 3.0 |
added 2341 characters in body
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| May 5, 2015 at 13:10 | comment | added | user21820 | Can you also put your excellent answer at math.stackexchange.com/q/248385 so that we can feel comfortable marking all subsequent questions about inverting fractions as duplicates of that one? =) | |
| Apr 13, 2015 at 23:39 | vote | accept | Joseph O'Rourke | ||
| Apr 13, 2015 at 17:04 | history | answered | mweiss | CC BY-SA 3.0 |