Rosie Posted June 16, 2012 Author Share Posted June 16, 2012 OK, so it's obvious we need a term other than "mental math" that encompasses the skills like making tens, adding/subtracting something that's close and then readjusting, using the commutative and distributive properties, etc. "Mental math based on a deep understanding of place value and mathematical laws" seems much too long! Any suggestions??? When I recommend to people that they teach their kids mental math, I want them to understand what I mean and not just assume I mean more drill or just doing the math in their head instead of on paper! (Literally, I used to try to do the traditional algorithm in my head because I thought that was mental math, and then I concluded that I wasn't good at mental math because I couldn't hold all that information in my working memory.) Quote Link to comment Share on other sites More sharing options...
stripe Posted June 16, 2012 Share Posted June 16, 2012 "Mental math based on a deep understanding of place value and mathematical laws" seems much too long! Any suggestions??? Given that we want our children to be strong and agile, may I propose.... Arithmegymnastics? Gymastomath? Quote Link to comment Share on other sites More sharing options...
Spock Posted June 16, 2012 Share Posted June 16, 2012 Can someone show me mental math with multiplication that isn't x9? I know 7x8 is 7 groups of 8 or vice-versa. They still have to memorize the answer right? Not necessarily. Other ways to find 7x8: 7x8 is also 7x4x2=28x2=(30x2)-(2x2)=60-4=56. (subtracting the doubled 2 is because 30 is 2 more than the number you want, and the 30 was doubled, so the extra 2 was also doubled--sounds complicated written down, but fit the way I thought as a child, and even now) 7x8= 7x4x2 = 28x2 = (20x2)+(8x2) = 40+16= 56 7x8=(7x7)+7, so: 7x7=49, 49+7=50+6=56 I was never taught mental math strategies in school, but I learned to do these things to get around math facts I hadn't learned yet. For some reason, this was both easier and more fun than just learning the math facts Quote Link to comment Share on other sites More sharing options...
Spy Car Posted June 16, 2012 Share Posted June 16, 2012 Not necessarily. Other ways to find 7x8: 7x8 is also 7x4x2=28x2=(30x2)-(2x2)=60-4=56. (subtracting the doubled 2 is because 30 is 2 more than the number you want, and the 30 was doubled, so the extra 2 was also doubled--sounds complicated written down, but fit the way I thought as a child, and even now) 7x8= 7x4x2 = 28x2 = (20x2)+(8x2) = 40+16= 56 7x8=(7x7)+7, so: 7x7=49, 49+7=50+6=56 I was never taught mental math strategies in school, but I learned to do these things to get around math facts I hadn't learned yet. For some reason, this was both easier and more fun than just learning the math facts I remember when we first started playing around with multiplication. I had demonstrated the distributive property with C Rods, but it was something we just sort of touched on. Some time later my son got a multiplication problem like 7x8. He said he didn't know what 7x8 was, but he knew 7x8 was the same as 8x7 because of the Commutative Law. He still didn't know what 8x7 was, but the next step surprised me. He said, "I know that 8x5 is 40 and 8x2 is 16 and I can split them that way because of the Distributive Law. So 8x7 is 56." It was one of those moments I'll never forget. Bill Quote Link to comment Share on other sites More sharing options...
Woodhaven Posted June 16, 2012 Share Posted June 16, 2012 :D For me, mental math is math the way Singapore does it. Quote Link to comment Share on other sites More sharing options...
letsplaymath Posted June 16, 2012 Share Posted June 16, 2012 Can someone show me mental math with multiplication that isn't x9? I know 7x8 is 7 groups of 8 or vice-versa. They still have to memorize the answer right? The point of my Times Table Series of blog posts is that with very little memorization (namely, the doubles and the square numbers), your children can learn how to calculate quickly not only the traditional times-table facts but a multitude of other multiplication puzzles as well --- and in the process, they will learn several important pre-algebra math principles: How to Conquer the Times Table, Part 1 How to Conquer the Times Table, Part 2 How to Conquer the Times Table, Part 3 How to Conquer the Times Table, Part 4 How to Conquer the Times Table, Part 5 Math Facts Are like Learning to Type Quote Link to comment Share on other sites More sharing options...
letsplaymath Posted June 17, 2012 Share Posted June 17, 2012 Perhaps "thinking strategies"? I picked that up from Elementary Mathematics for Teachers and have started using it in my PUFM blog post series. Quote Link to comment Share on other sites More sharing options...
Rosie Posted June 17, 2012 Author Share Posted June 17, 2012 Perhaps "thinking strategies"? I picked that up from Elementary Mathematics for Teachers and have started using it in my PUFM blog post series. Possibly. I'd like a term that clarifies an incorporation of place value (making tens, etc.), though, probably because that is the specific thing that brought my "Aha!" moment a few years ago. I suppose the word "thinking" in there may clue people in, but, then, maybe they'd be just as likely to think that recalling memorized facts is "thinking." Quote Link to comment Share on other sites More sharing options...
Rosie Posted June 17, 2012 Author Share Posted June 17, 2012 Given that we want our children to be strong and agile, may I propose.... Arithmegymnastics? Gymastomath? Or Gymathtics! :lol: People would probably just think I had a lisp.... Quote Link to comment Share on other sites More sharing options...
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