How did you learn multiplication?

[Leros]

We had to memorize the 12x12 multiplication table in 4th grade. We just wrote it out over and over, so I ended up memorizing both ways.

For numbers above 12 (except for a few squares), I just do the computation in my head.

 

[Leros]

10s were easy so I would do....

10 x 16 = 160
8 x 10 = 80
8 x 6 = 48

288

I would take a slightly different approach:

18x16
= 20x16 - 2x16
= 320 - 32
= 320 - 30 - 2
= 290 - 2
= 288

 

[Imp]

Mommy made me memorize entire god damn tables before we even touched it in school.

 

[yhelothar]

Through building sundaes.
We had to drill through from 1x... to 12x..., 50 questions each.
We'd get three minutes to get them all right.
Each one we'd pass, we'd get an extra layer on our sundae. 1 got you the bowl; 2, a banana; 3, ice cream; etc..

I aced it easily with my asian math powers.

 

[Rage187]

When I was in 1st grade, I would get timeouts and be put in a desk/cube with nothing but a multiplication chart. I was put there a lot.

 

[alzan]

Did you memorize the bigger number multiplying the smaller number or just the smaller number multiplying the bigger number?

Example:

Did you memorize 8 x 4? Or did you only memorize 4 x 8?

I memorized 2 x 16.

What school did you attend?

 

[Cerb]

Did you memorize the bigger number multiplying the smaller number or just the smaller number multiplying the bigger number?

Example:

Did you memorize 8 x 4? Or did you only memorize 4 x 8?

I learned with tables and flash cards. Nothing about order, except to simplify few digits * many digits.

I would do 16x20 - 32 personally.

I would do 16^2+16*2, since I know the low powers of 2.

grade school.

high school

College. 😉

I never could manage the tricks like that, because they would either lead me off by a digit, or not work every time. I just did it longhand. I didn't see how they saved much time, either, since the paper was just to keep place, not actually do all the work. In college, I could use the calculator much less than up through HS (however, a calculator that could load programs that could do symbolic solving was a requirement, so...).

 

[mikeford]

Drill and tables. One of my HS teachers couldn't sleep one night, memorized through 25x25 he said it actually was quite useful.

Going beyond 12x12 is more than gross.

 

[Fenixgoon]

i think we learned times tables through 12.

also i do all multiplication vertically

so in one of the examples, 32 x 44

32
44

_128
1280
_____
1408

 

[her209]

Convert the umber to binary and then multiply.

 

[Mr. Pedantic]

A teacher taught me to put the bigger number on top and smaller one below. So it was a vertical format like this without the "0"s

008
x04
------
32

But she's dead now I think because I'm an old guy and she looked kinda old as I remember so she's gotta be dead by now.

Principles only get you so far. At some point you have to define the products of a bunch of one-digit prime numbers and they will have to be memorised.

 

[mikeford]

Convert the umber to binary and then multiply.

Convert to binary then shift and add, repeat.

 

[Thebobo]

I would take a slightly different approach:

18x16
= 20x16 - 2x16
= 320 - 32
= 320 - 30 - 2
= 290 - 2
= 288

Lst year of hichscool I worked at a full service gas station (thats all there were ) I was the evening shift manager and handled the money most payments were cash and I was master on that machine and adding in my head by using 10 base. Thats why I add in my head when I multipy

 

[Carson Dyle]

I add when I subtract. (From years of playing darts.)

417 - 68
= 417 + 32 - 100
= 349

 

[Mixolydian]

I still don't know multiplication. :hmm: