z*s
发帖数: 1695 | 1 Got this email from one of friend.
Finger math trick is very interesting, after you finish reading this, i’m
sure that the multiplication of 9th will become easy for you.
Let’s look one example,
Problem: 9×4=?
Answer: 36
Trick:
Spread your two hands, and place them on a table in front of you.
To multiply by 4, fold down the 4th finger from the left. To multiply by 7,
it would be the 7th finger and so on.
Count how many fingers on the left side of the folded down finger. it is 3.
Then count the fingers on the right side of the folded down finger, it is 6.
So 9×4=36.
Summary: To multiply x with 9, fold that xth finger down, and then count
each sets of fingers on left and right side of the folded finger. | m**k
发帖数: 18660 | 2 这么细节的东西。。。也要我们研究？？
,
【在 z*s 的大作中提到】
: Got this email from one of friend.
: Finger math trick is very interesting, after you finish reading this, i’m
: sure that the multiplication of 9th will become easy for you.
: Let’s look one example,
: Problem: 9×4=?
: Answer: 36
: Trick:
: Spread your two hands, and place them on a table in front of you.
: To multiply by 4, fold down the 4th finger from the left. To multiply by 7,
: it would be the 7th finger and so on.
| z*s
发帖数: 1695 | 3 we can tell kids the trick
【在 m**k 的大作中提到】
: 这么细节的东西。。。也要我们研究？？
:
: ,
| K*******l
发帖数: 3747 | 4 不是不鼓励动指头吗？：p
【在 z*s 的大作中提到】
: we can tell kids the trick
| z*s
发帖数: 1695 | 5 I agree but sometimes they do it anyway.
【在 K*******l 的大作中提到】
: 不是不鼓励动指头吗？：p
| T*****u
发帖数: 3257 | |
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