quick trick: mind-blowing math tricks
It’s no secret that I am not a math person.
And it’s really no secret that my kids’ math skills will soon (hopefully!) surpass my own.
I cried my way through calculus (no joke), and I’d rather walk on fire than take another statistics course. While my friends would quickly calculate the final cost of that awesome pair of shoes at 25% off with a $14.75 store credit and (shhhh!) a pal’s employee discount, I’d still be stranded at the 25% off part.
Or I’d pull out my super-secret tiny purse calculator. (It was before we all had smartphones, thank you.)
I have to think through or write out just about any sort of math computation.
So I’m a huge fan of tricks. And songs. And just about anything that makes this math mountain easier for me to climb.
But are ‘math tricks’ okay for kids to learn? What do you think?
Here’s the skinny on a math-happy Quick Trick I learned recently that I find so totally cool. . .
- Mind-Blowing Math Tricks: A few weeks ago, someone told me about the 9 times tables trick. At this point, I have no idea who that person was (sorry!), but if you were the person, please remind me.
I had never heard of it before, so when I showed Maddy, she was pretty amazed. So very happy.
It goes like this:
- 9 times tables trick– take 9 x 3 and put your third finger from the left down. Then count the number of fingers on the left side of that finger (here you get 2) and on the right side of the finger (you get 7). Put those numbers together (27) and there’s your answer. 9 x 3 = 27.
Why does it work? I have no idea. But it’s so cool.
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Maddy tries out her ‘new’ multiplication by 9 trick.
Want to read about some tricks for:
- multiplying by 4?
- multiplying by 11?
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- multiplying by 12?
- multiples of 3?
And want to know why the multiplying by 9 trick works? Check out 5 Cool Math Tricks You Didn’t Know over on Mom’s Homeroom; it’s full of mind-blowing mathy-math tricks that may make this road a little easier for your kiddos.
But I especially love what math expert, Laura Laing believes about these crazy math tricks. ‘Kids can benefit from knowing math facts cold’ she explains, because ‘when the arithmetic is simple, children are allowed to focus on more complex concepts’. We get that, right? Just like our kiddos need to have a solid knowledge base of sight words so they can focus on comprehension instead of decoding.
However, Laura feels that children should have a strong foundation of basic math skills before the ‘math tricks’ are introduced–this is usually around grades four or five. (Shoot, so poor Maddy will be off here. . . )
She explains that ‘straight memorization is not always the best’ and that ‘when kids spend a great deal of time really unpacking what these math concepts mean, their understanding is far more likely to extend toward many other concepts’ (5 Cool Math Tricks. . . ) which . . . well, yes, yes, and yes! Save the tricks for a little later so the understanding is a little deeper.
But a few tricks in a kid’s back pocket won’t hurt, right?
Do you have any other math tricks that work for your little ones? Have you shared them with your kids already, or are you waiting for a strong, foundational skill-set to develop? I’m so curious! Do tell. . .
fyi: This blog post is part of an incentivized online influencer network for Mom’s Homeroom. Mom’s Homeroom is brought to you by Frosted Mini-Wheats.
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Jenny told me about your blog and I just wanted to tell you that I love it! I remember learning the nine trick at one point and thought it was just magic. I was one of those kids that didn’t take fast to multiplication tables and this little trick helped me out so much.
25/05/2012
thanks so much, Melinda!!! I truly appreciate your kind words and the fact that you took time to comment here–means so much! Three cheers for math tricks!!
27/05/2012
I learned that “9x” math trick from the movie Stand and Deliver. At least, I think it was Stand and Deliver.
26/05/2012
SERIOUSLY!!?? how hilarious!! Thanks for sharing, Amy!
26/05/2012
We are. Dealing with a math hater in our house so I’m looking back at your old posts for some inspiration. Here’s two tricks I learned: one is for 6×6 through 10×10. There is a video going around for that. It’s like the nines trick. I think you can google it and find it. The other was a Vedic math trick (say what?) for multiplying two digit numbers. It involves drawing intersecting lines and counting the cross points. It’s another video. I can’t explain well but if you’re interested I’ll send you the links.
27/09/2012
Oh, Dana!!! A math hater. Oh, the joys. . . I will DEF check out the tricks you mention here. . . please–if you have the time and I know you’re crazy busy, send me the links and I’ll know exactly what you’re talking about. I will also google but you never know what you’ll find. . . thanks for reading, my friend and HUGE thanks for taking the time to write!!
02/10/2012
I also have a math trick that will really blow your mind, it goes like this
here the steps to follow:
1.think a number, any number.
2.then i want you to multiply that number by 2.
3.when you already get the answer, add 24.
5.and then divide it by 2.
6.lastly, the answer that you will get subtract it by the number that i have told you to think in the first step….
i guess the answer would be 12.. am i right!. tsk!!! C:
i hope you amazed……
-vhorjune!
19/11/2012
Oh how I love your website and am so inspired!
One question about the flash cards for example. I can see me pulling out the flash cards in the car etc. and my 2nd grader groaning in agony. What’s your advice?
Thanks
Jessica
07/04/2013
oh man! Jessica–then maybe try to incorporate them into games RIGHT away! Can you try some of the races I write about? use silly things like wands or flashlights? involve candy? speed races? make a limit–call it ’5 and out’ or ‘take 10′ or ‘mom’s mad math’ or something?
Let me know how it goes, and just stressing that there’s no option–people need to know these facts to grow their brain–and doing it regularly may ease the eye rolling and snickering. . .
10/04/2013
i honestly don’t remember how i ended up reading ur blog post [internet kills time softly lol!]. Anyway that is a fine post. Just wanted to share my story. Okay, i got to the US [from india] last year and met my girlfriend after i blew her mind with the same trick albiet in an engineering style. You see this trick can be expanded, take 9999 and ask some one to pick a random four digit number, say 5678. Ask them use a calculator to get the product while you work ur magic- subract 1 from the number, u get 5677 and now subract each digit from 9. Like 9-5, 9-6,9-7, 9-7. Write the number together to get 56774322. And this works everytime u try to multiply 9999….n times with a ‘n’ digit number.well i do know quite a few tricks of this kind. And as for sharing with kids, this only helps them getting more into numbers. I still remember when i pulled this of in my 6 th grade and all the amazement on my friends’ faces and it just made me want to learn more. i picked up math and now i’m a mechanical engineer. Mathematics rocks!
10/04/2013