Always remember your times tables with these secret tricks

Your fingers are secretly a powerful calculator.

0:00 intro
0:23 multiply 6 to 9
7:18 why works 6 to 9
11:52 multiply 11 to 15
15:40 why works 11 to 15
17:14 times table 9
19:28 why works table 9

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[verkuilb]

There’s a better, much faster way to find a product like 7 x 8. Instead of counting out fingers, adding certain fingers, and multiplying others—you just go: “Hey! I learned these in elementary school! Seven times eight is fifty-six!” And then you write it down, while your friend is still figuring out how many fingers he has…

[augtsu]

Sometimes it is simply easier to memorize the times table rather than the different tricks for the answers. One winter I was working on a 6 month job site assignment where the coworkers were heavy into the game of darts. By the end of my assignment I was able to keep track of 6 players (three throwers per side) scores, adding up each throw then subtracting it from the running score in my head. Being able to do this was easier than I first thought.

[RamiroCharriol]

Thanks Presh, these are very good, ive been using the method for 9 since very young, but the 6 to 9 i didnt knew, and its really cool

[corvusmoneduloides]

Teacher: Johnny, what is 3+4?
Johnny counts on his fingures and says "7".
Teacher: You shouldn't count on your fingures, so put your hands in your trouser pockets. Now tell me what is 5+5.
Johnny (counting again): 11

[Dreamprism]

2:30 This trick with the fingers is the same mathematically as the "X trick" that was taught centuries ago in England as a way to multiply numbers from 6 to 9 & likely the reason we use an "x" as a times symbol in mathematics.

[philrobson]

It’s easier to learn the times tables.

[PolarFren]

THIS IS WHY I LOVE THIS CHANNEL THIS IS INSANE!!!!

[Meek]

With the times table 9 I always remembered that multiplying it from 1 to 10 the sum of the first and last digits always equal to 9 and the first digit a-1 while second is 10-a

[technik-lexikon]

My favourite "finger math" trick is using the thumb and phalanges to count up to 144.

[howareyou]

This feels similar to using fingers to count and do addition...
It helps kids, especially those who are not particularly interested in math, to get started.
But at the end of the day, it's much easier and more convenient to just memorize the basic addition and multiplication table.

[JaniLaaksonen]

I only memorized times tables up to 6. I used the 3rd trick for 9s times table and only memorized 7x7, 7x8 and 8x8 since the rest of the 7 and 8 times tables are parts of other times tables.

[hadassahsoddsandends]

This was so much fun! I knew the third set already, except I learned it palms facing me, and starting with the left thumb as "one". The first set was nice, and I can use it in tutoring, even though I have all of those memorized anyway. The finger working is great for tactile students! The second set was the "Wow, I needed that" for me! This is very cool! Thank-you!

[pierreabbat]

If the difference is even, as in 12×14, it's easier to memorize the squares and subtract two squares. 13²-1²=168.

[Bob]

This was slightly fun. But there are of course very good reasons why these hacks are not taught in school. It is much better to memorize the multiplication table.

[JohnJones-pugi]

Of interest. bit obvious in class! Given my lack of memory for rote tables, I worked out a trick for 6-9 which was to use the tens complements, multiply them and add ten times the tens complement of their sum. Eg 7*8 complements are 3, 2 gives 3*2 + 10*(10 - (3+2)) = 56. Easier done than said! Why it worked is obvious.

[jeremiahlyleseditor]

Great Video.
This trick I've never seen before.

[farrier]

Fascinating! However, the easiest way to multiply any pair of numbers between 2 and 12 is to learn the "Times Tables" by rote.
There are other tricks to do mental arithmetic. To multiply any number by 9, for example. Multiply (n) by 10 and subtract (n).
I was taught a lot of this stuff at school, too many years ago than I care to contemplate but it's never left me.

[marvhollingworth]

I already knew the trick for the 9 times table, I taught it my daughter & she uses it at school. I struggled to follow the 2nd trick but it & the 1st trick are more complicated than just knowing times tables. I have my own methods of mentally working out bigger multiplications. For example, for 12 x 13, I know 12 x 12 = 144 so I just add another 12 on. To multiply any number by 18, I can double the number, put a 0 on the end & take off double the number I started with. Much easier.

[verkuilb]

The fact that all of us (including Presh) are using our knowledge of multiplication tables to verify the accuracy of these methods, says all you need to know about which method is the gold standard against which all the others are compared.

[abdullahnuridah]

Thanks for explaining how this tricks works..