13x10 + 2x13 ... easier...
Kajmunk4A2 2 months ago
It's basically just FOIL with digits instead of terms.
(10+2)*(10+3) = 10*10+2*10+10*3+2*3 = 100+20+30+6 = 100+50+6 = 156
Keiko8383 9 months ago
@Keiko8383
True and simple, although many people don't know how this works, and only do this:
(10+2)*(10+3) = 10*10 + 10*2 + 3*10 = 150.... they just forget some little parts and with using these tricks they won't.
123mannetje 9 months ago
this is pretty useless...
how about just doing it inside your head?
drakesolar 1 year ago
lol, 3 + 2 = 3... ow oeps... 5 :P
Lainfan 1 year ago
18*64 = ?
its inefficient
MrShitpickle 2 years ago
Duh.. I already said that before.
123mannetje 2 years ago
Comment removed
PlanlosYTuser 11 months ago
To the skeptics: This will work even with digits greater than 4...it's merely a pictorial way to look at multiplication, as you've always done:
12 * 13 = (10 + 2) * (10 + 3)
= 10*10 + 10*3 + 2*10 + 2*3
= 100 + 5*10 + 6*1
So you would count 1 dot on the left, 5 in the middle, 6 on the right, and then write 156.
Mowicz 3 years ago
@Mowicz Yep, it's FOIL with digits instead of terms. (or with terms if you break it out like you did)
or you just take a calculator ..
FigureNine 3 years ago
Stupid ... -_-"
You don't like math, do you?
123mannetje 3 years ago
No, i just go outside some now and then. :S
this only works with numbers without 4 and up
D=digits
1D*1D easy on about 9% of all problems
1D*2D easy on about 2.7% of all problems
2D*2D easy on about .81% of all problems
A1HitterQuitter 3 years ago
What method do you mean? The first method always work, it's only not efficient if you use nubers higher than 5 like 9
bedankt ;) ;)
FuckGreenDay02 3 years ago
welke methode gebruikte je?
to do 22x15... all u need to do is just half 22 which is 11 and then double the 15 do 30.. no u have 11x30... which is equal 330... easy?
DuangJai99 4 years ago
Yes, it is. every thing times 11 is easy. =P
123mannetje 4 years ago
if 22x15= how to do
jthntia 4 years ago
the first one will help you.
the last trick will only work with nummbers in the ten.(10 - 19)
As a number is higher than 19 you have to do it like this:
12 x 13 , is than 3 x 2 (13-10=3)
12 x 21 , is than 11 x 2 (21-10=11)
haha... nice one... ;)
RuGeaR 4 years ago 2
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13x10 + 2x13 ... easier...
Kajmunk4A2 2 months ago
It's basically just FOIL with digits instead of terms.
(10+2)*(10+3) = 10*10+2*10+10*3+2*3 = 100+20+30+6 = 100+50+6 = 156
Keiko8383 9 months ago
@Keiko8383
True and simple, although many people don't know how this works, and only do this:
(10+2)*(10+3) = 10*10 + 10*2 + 3*10 = 150.... they just forget some little parts and with using these tricks they won't.
123mannetje 9 months ago
this is pretty useless...
how about just doing it inside your head?
drakesolar 1 year ago
lol, 3 + 2 = 3... ow oeps... 5 :P
Lainfan 1 year ago
18*64 = ?
its inefficient
MrShitpickle 2 years ago
Duh.. I already said that before.
123mannetje 2 years ago
Comment removed
PlanlosYTuser 11 months ago
To the skeptics: This will work even with digits greater than 4...it's merely a pictorial way to look at multiplication, as you've always done:
12 * 13 = (10 + 2) * (10 + 3)
= 10*10 + 10*3 + 2*10 + 2*3
= 100 + 5*10 + 6*1
So you would count 1 dot on the left, 5 in the middle, 6 on the right, and then write 156.
Mowicz 3 years ago
@Mowicz Yep, it's FOIL with digits instead of terms. (or with terms if you break it out like you did)
Keiko8383 9 months ago
or you just take a calculator ..
FigureNine 3 years ago
Stupid ... -_-"
You don't like math, do you?
123mannetje 3 years ago
No, i just go outside some now and then. :S
FigureNine 3 years ago
this only works with numbers without 4 and up
D=digits
1D*1D easy on about 9% of all problems
1D*2D easy on about 2.7% of all problems
2D*2D easy on about .81% of all problems
A1HitterQuitter 3 years ago
What method do you mean? The first method always work, it's only not efficient if you use nubers higher than 5 like 9
123mannetje 3 years ago
bedankt ;) ;)
FuckGreenDay02 3 years ago
welke methode gebruikte je?
123mannetje 3 years ago
to do 22x15... all u need to do is just half 22 which is 11 and then double the 15 do 30.. no u have 11x30... which is equal 330... easy?
DuangJai99 4 years ago
Yes, it is. every thing times 11 is easy. =P
123mannetje 4 years ago
if 22x15= how to do
jthntia 4 years ago
the first one will help you.
123mannetje 4 years ago
the last trick will only work with nummbers in the ten.(10 - 19)
As a number is higher than 19 you have to do it like this:
12 x 13 , is than 3 x 2 (13-10=3)
12 x 21 , is than 11 x 2 (21-10=11)
123mannetje 4 years ago
haha... nice one... ;)
RuGeaR 4 years ago 2