prairiewindmomma Posted August 20, 2012 Share Posted August 20, 2012 We took a break from MUS for a while to zip through Singapore Math....I'm putting my 2E child back through MUS for review and we're getting to chapter 10 which is about dividing fractions..... Mr. Demme's method seems way more complicated than how I learned in school. He wants the student to divide using the rule of four. I learned to flip and multiply. Do I need to follow his methodology for some greater math purpose that I don't understand, or can I teach my son to flip and multiply? For those who aren't following what I'm saying: His method: 3/6 / 1/2 = 6/12 / 6/12 = 6/6 /1 = 1 My method: 3/6 / 1/2 = 6/6 = 1 OR His method: 2/3 / 3/6 = 12/18 / 9/18 = 12/9 /1 = 12/9 My method: 2/3 / 3/6 = 12/9 Quote Link to comment Share on other sites More sharing options...
coffeefreak Posted August 20, 2012 Share Posted August 20, 2012 We taught dd both ways. He teaches them using the rule of four to show them WHY when you flip and multiply it works. DD does well with that kind of teaching, even if it totally screws me up. I just want to know how to get it done the easiest way possible. Blessings! Dorinda Quote Link to comment Share on other sites More sharing options...
5LittleMonkeys Posted August 20, 2012 Share Posted August 20, 2012 Same as above. I teach the rule of four so they get why inverting and multiplying works and then we never do it that way again. :D Quote Link to comment Share on other sites More sharing options...
MerryAtHope Posted August 21, 2012 Share Posted August 21, 2012 We taught dd both ways. He teaches them using the rule of four to show them WHY when you flip and multiply it works. DD does well with that kind of teaching, even if it totally screws me up. I just want to know how to get it done the easiest way possible. Blessings! Dorinda Same as above. I teach the rule of four so they get why inverting and multiplying works and then we never do it that way again. :D LOL, yes. You really don't do it for long, but I think it helps to know that fractions really CAN be divided, rather than having no idea why a trick (really a short-cut) works. I was never taught that fractions could actually be divided when I was in school, so I appreciated this aspect. Anyway, he'll get to invert & multiply soon :). Merry :-) Quote Link to comment Share on other sites More sharing options...
prairiewindmomma Posted August 21, 2012 Author Share Posted August 21, 2012 Thanks! Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.