fluffybunny Posted January 30, 2014 Share Posted January 30, 2014 Can anyone direct me to video series or other source for mental maths. We already have googol's multiplilcation vacation. He most needs help with mentally doing maths like 33-24 or 45+73. I do it in my head by pulling them apart, and I don't know how I learnt it, nor how to teach it. Khan academy looks too advanced. Ds13 went to school for the first 5 years and I doubt he learnt anything at all maths-wise, having HFA and always being taken out of the classroom as he couldn't handle the noise. We did start back at the beginning of Math U See when we first started hs'ing. He knows the formulas and methods to do maths now, and we're close to ending the decimals unit before starting prealgebra. But he is soooooo slow in doing long division etc, because he can't work in mental maths, and long division has a lot of 24-13 or 4354-345 etc. Zeta is taking forever to finish because of this! Quote Link to comment Share on other sites More sharing options...
wapiti Posted January 30, 2014 Share Posted January 30, 2014 You might consider this topic book, though you might also email the author and ask which of her topic books would be best for mental math. http://www.mathmammoth.com/add_subtract_3.php; maybe this one would be better, I'm not sure http://www.mathmammoth.com/add_subtract_2B.php Quote Link to comment Share on other sites More sharing options...
idnib Posted January 30, 2014 Share Posted January 30, 2014 Singapore 2 and 3 have lots of tricks for mental math (addition and subtraction). Quote Link to comment Share on other sites More sharing options...
Penguin Posted January 30, 2014 Share Posted January 30, 2014 We recentlty started watching The Secrets of Mental Math from the Great Courses. We love it! The types of problems that you mentioned are covered right away. And there is a booklet with additional practice problems. This particular course is often available for deep discount, so if it is full price right now you could wait for it and get started with something else in the meanwhile. Quote Link to comment Share on other sites More sharing options...
fluffybunny Posted January 31, 2014 Author Share Posted January 31, 2014 Thank you for your suggestions: I am looking into them now. Quote Link to comment Share on other sites More sharing options...
EndOfOrdinary Posted February 3, 2014 Share Posted February 3, 2014 Your "pulling them apart" is called expanded form in math-see. 73 becomes 70 + 3. This makes it much easier to do mental math because as long as the student can hold the numbers in their brain, adding 50+3+20+9 is much simpler than 53+29. I had my son practice by writing the expanded form (we call it ripping them apart) on paper first. In the above problem it would look like 50+20 = 70 then 3+9=12 then 70+12=82. He only had to write then out for about 1 week before he started doing them faster and faster in his head. We also practiced visualizing the numbers and moving them in the air when he first began. Quote Link to comment Share on other sites More sharing options...
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