#JamielElizabethPH: Math Trick #01

Sunday, September 11, 2011

Math Trick #01

There was a time during my elementary days that i feared Math the most!
It was when my 3rd grade teacher announced that she'll be calling us randomly to recite two of the multiplication table!
And the catch is, she'll be the one to decide which number will we get and that made my knees wobble!

The multiplication table of 1 is a no-brainer, BUT, let's face it! even adults sometimes are having a hard time doing numbers in their heads! hihi
I can mentally calculate tables 2 to 5, and table of 10 is as no-braner as the multiplication of 1. :D
Then comes, 6, 7, 8 and 9. *swallow hard

I was like 8 years old, staring the multiplication table with fears in my eyes for tomorrow I might face the tragedy of the year! hehe

Then, my hero came! yay!
My dad coach me and learned a trick that I wanna share with you as well.
You might already knew this, and forgotten about is, so this will help you refresh a Math skill! *winks

The Multiplication by Hands - applicable for 6, 7, 8, 9 and 10 as multiplier and multiplicand

Step 1 - look at your hands, your thumbs represents number 10, the index finger as 9 and so on, hence, your pinky is number 6.
Step 2 - let's set an example. So lets say its 7 x 8. (No calculators pls! that's cheating!) What you do is connect the fingers representing 7 and 8.
From the connecting fingers, count each fingers downwards by ten. So thats 10, 20, 30, 40, 50.
Step 3 - Count the remaining left fingers and add it to the sum of the remaining right fingers. so that's 3 x 2 = 6

Step 4 - Add the sum of step 5 and 6, so that will give you 50 + 6 = 56. Awesom I know! :D

Before the recitation, thank goodness! I mastered the trick. I felt more confident and I'm sure enough that I can handle the task tommorow. But I didn't stop staring at the multiplication table especially the table of 9.

Take a look:

Photo Courtesy of helpingwithmath.com

Did you get what I got 16 years ago?

I first observed that the digits of the answers if added will always be 9.
And aside from tables 1 and 10, 9 is a no-brainer too! you just have to know the trick! ;)
Example: 9x7. Instead of counting 9 + 9 + 9 + 9 + 9 + 9 + 9... All you need to do is add zero to the digit you are multiplying to 9, in this case 7 will become 70. Then we have to minus that digit to the new set of number, 70 - 7 = 63.
In short: 8 x 9 = 80 - 8 = 72. awesome!

Do you have more math tricks to share? Comment down below, its time to share yours! Click like for more math tricks! :P

Note: I am not a math genius. i just have a trick or two on my sleeves that i wanna share. hope that won't break your heart! <3