Last time, a presenter presented at our school about their mathematics tuition. In the presentation, he taught us a trick to make our division a piece of cake. (Sorry I forgot to post this earlier 🙂 )
However, this trick can only be used when a number is divided by five.
Instead of doing the ‘hard’ way (‘/’ means divide),
40 / 5 = 8
you do the easy way:
First multiply 40 by 2:
40 x 2 = 80.
The answer is 80, right?
Now, you take away the 0.
8
It becomes 8, and that’s the answer.
Isn’t that simple?
But if the number doesn’t end in 0…
41 x 2 = 82
You put a decimal before the last digit.
8.2
That’s the correct answer, right?
Now, this could be useful when dividing biiiig numbers, such as 192123789.
192123789 / 5 = ?
Well, that looks hard, doesn’t it?
It doesn’t?
But it will take more time.
If you use this method, it would be quicker.
x192123789
x            2
x38424757.8
If you don’t like multiplication, simply do this way:
+ 192123789
+ 192123789
+38424757.8
I hope you will find this information helpful. 🙂
Great tips on how to teach children to do matt. I am a first time Mom. You blog is going to be very useful for me in years to come 🙂
Thank You,
Giovanna Garcia
Good, I have similar post in my blog about quick mathematics calculation. If this useful trick does exist in my school time, how good it is.
.-= Simon Liew´s last blog ..Instant Multiplication (Part 1) =-.