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#### woodnthings

· where's my table saw?
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I've seen the infomercial Brainetics, with the math wizard and his kids, pretty cool. I don't know how they do it, but here's what I do:

example: what's 16 X 24?

10 X 24 is 240, 5 X 24 is half of 240 or 120. Add them. need 1 more 24 to make 16, 10 +5 + 1 = 16

240 + 120 = 360 + 24 = 384

I use 10's and 5's and and then single numbers under 5. Or 5 minus 1 is 4.

I'm lost on division.... :thumbdown:

Anybody got other tips or tricks?

· Log dog
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#### WillemJM

· Registered
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I've seen the infomercial Brainetics, with the math wizard and his kids, pretty cool. I don't know how they do it, but here's what I do:

example: what's 16 X 24?

10 X 24 is 240, 5 X 24 is half of 240 or 120. Add them. need 1 more 24 to make 16, 10 +5 + 1 = 16

240 + 120 = 360 + 24 = 384

I use 10's and 5's and and then single numbers under 5. Or 5 minus 1 is 4.

I'm lost on division.... :thumbdown:

Anybody got other tips or tricks?
Bill, I'm not smart enough to do that. Found that out the hard way. The last time I tried that I cut my board too short and had throw it away.

So now I do it on five different calculators and if I get the same answer five times, I then do it on my laptop. If I still get the same answer, I measure six times on my board, using a different color pencil each time. If all the marks align, I cut my board. So, now I am trying to figure out why I still cut my last board too short???? Any suggestions. :blink:

Just joking.

#### Kenbo

· HALL OF FAMER
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You do it the same way that I do Bill. It pretty much works for me and when it doesn't, I use Dominick's method.

#### cabinetman

· Old School
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Now this is an interesting topic. There was a time immediately after hurricane Wilma when in my area we lost all power for about 17 days. There was really nothing to do. It was extremely quiet outside, as there was little to no automobile traffic because there was no gas. The roads were strewn with tree limbs and debris and many were impassable. So, when I say, there was nothing to do, you didn't want to do anything. The daytime temperatures got up to the mid to high 90's. You could stand still and just sweat.

I found at that time what a perfect time to practice doing math in my head. I could just sit outside under the shade of what was left of a huge Avocado tree and practice additions and subtractions. My methods were a lot like yours. I used a simple step by step evaluation that fell in place.

I will say if it gets too difficult you could use the binary system and then you'll only have zeros and ones to deal with. But, if you really want to stimulate your mind, use the octal, or hexadecimal system. Like I said, that there wasn't anything to do, and if I made a mistake, it didn't matter a hill of beans. I could just erase my mental image and start over. A wrong answer didn't create any disasters.

But, if I'm figuring out a woodworking or cabinet layout, a wrong answer could wind up with a kitchen countertop that's 6' high, and wall cabinets 6" high, and instead of fitting on a wall that's 7' long they end up 17' long. So, what was the consequence of making a mistake. Lets see...lost time, material waste, and aggravation. If it's necessary to do any math, I write everything down so I have a record of what the details are and what they apply to. I don't do any project planning and proceed without making a drawing of some sort.

It does seem very simple to start a project with what's in our mind. But having some reference to back up our thoughts might be easier than trying to remember all the numbers. As for your despair with division, try this method.

.

#### woodnthings

· where's my table saw?
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32,620 Posts
Discussion Starter · ·
cell and "smart" phones have a calculator

No need to carry a separate calculator anymore if you're packin' smart phone.
Sometimes while driving I need to calculate something, hands will remain in the 2 and 10 steering position, so I try to do it in my head. It impresses my son, but he won't let on, he just reaches for his phone. :laughing:

I'd like to get the Brainetics program someday. It's very impressive to me anyway.:yes:

#### cabinetman

· Old School
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Sometimes while driving I need to calculate something, hands will remain in the 2 and 10 steering position, so I try to do it in my head. It impresses my son, but he won't let on, he just reaches for his phone.
What might impress your son more, and act as a role model for him would be to concentrate on your driving.:yes:

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#### woodnthings

· where's my table saw?
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32,620 Posts
Discussion Starter · ·
he's been properly trained, thank you

What might impress your son more, and act as a role model for him would be to concentrate on your driving.:yes:

.
I've taken 2 Police/Civilian Motorcycle Training classes, have experience on the GM proving Ground Facility, drive on icy hilly, roads all winter. He passed his cycle training exam with 100% score and drives as well or better then I. He started steering when he was 4 years old sitting on my lap. All he needs is experience and that will come with experience.
I really don't need any advice on how to raise my son. :no:
He just received the Dean's Award in Auto Technology and will graduate at the top of his class.... no reflection on my parenting skills of course .... :yes:

#### GeorgeC

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I've seen the infomercial Brainetics, with the math wizard and his kids, pretty cool. I don't know how they do it, but here's what I do:

example: what's 16 X 24?

10 X 24 is 240, 5 X 24 is half of 240 or 120. Add them. need 1 more 24 to make 16, 10 +5 + 1 = 16

240 + 120 = 360 + 24 = 384

I use 10's and 5's and and then single numbers under 5. Or 5 minus 1 is 4.

I'm lost on division.... :thumbdown:

Anybody got other tips or tricks?
That is pretty much how I do it. I break the problem into smaller parts. Sometimes I may vary it a bit.

Division is pretty much the same thing. Break the problem into smaller parts.

George

#### cabinetman

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I've taken 2 Police/Civilian Motorcycle Training classes, have experience on the GM proving Ground Facility, drive on icy hilly, roads all winter. He passed his cycle training exam with 100% score and drives as well or better then I. He started steering when he was 4 years old sitting on my lap. All he needs is experience and that will come with experience.
I really don't need any advice on how to raise my son. :no:
What's all that have to do with some well intended safety comments?

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#### del schisler

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Bill, I'm not smart enough to do that. Found that out the hard way. The last time I tried that I cut my board too short and had throw it away.

So now I do it on five different calculators and if I get the same answer five times, I then do it on my laptop. If I still get the same answer, I measure six times on my board, using a different color pencil each time. If all the marks align, I cut my board. So, now I am trying to figure out why I still cut my last board too short???? Any suggestions. :blink:

Just joking.
cut from the wrong end ??

#### woodnthings

· where's my table saw?
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32,620 Posts
Discussion Starter · ·
nothing of course

What's all that have to do with some well intended safety comments?

.

#### cabinetman

· Old School
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I'm here for ya buddy...just sayin'.:yes:

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#### TomC

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2,304 Posts
woodnthings said:
I've seen the infomercial Brainetics, with the math wizard and his kids, pretty cool. I don't know how they do it, but here's what I do:

example: what's 16 X 24?

10 X 24 is 240, 5 X 24 is half of 240 or 120. Add them. need 1 more 24 to make 16, 10 +5 + 1 = 16

240 + 120 = 360 + 24 = 384

I use 10's and 5's and and then single numbers under 5. Or 5 minus 1 is 4.

I'm lost on division.... :thumbdown:

Anybody got other tips or tricks?
I do it basicly the same way.

I would do it this way

20 x 24 = 480

4 x 24= 96

480 - 100= 380 + 4=384

#### jschaben

· John
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3,028 Posts
I've seen the infomercial Brainetics, with the math wizard and his kids, pretty cool. I don't know how they do it, but here's what I do:

example: what's 16 X 24?

10 X 24 is 240, 5 X 24 is half of 240 or 120. Add them. need 1 more 24 to make 16, 10 +5 + 1 = 16

240 + 120 = 360 + 24 = 384

I use 10's and 5's and and then single numbers under 5. Or 5 minus 1 is 4.

I'm lost on division.... :thumbdown:

Anybody got other tips or tricks?
Hi Bill, I do similar. In your example 16x20 = 320 and 16x4 = 64 so 320 + 64 = 384. Just cut out the 5's step. Gets a little more complicated doing 3 digit numbers, usually go with powers of ten there. Powers of ten also work with division as instead of adding the accumulated exponents, you subtract them. :smile:

#### mengtian

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I am a math nut. My first degree before going in the army was a B.S Math.

I still read about mathematicians and have always been fascinated with some of the greats. I like to "show off" by telling people what day of the week it would be for a given date. I have it down to about 10 seconds on good days. BTW: it is called the Doomsday Rule. Devised by Jeff Conway.

http://people.cst.cmich.edu/graha1sw/pub/doomsday/Doomsday.html

Math really helps with long range shooting which is a hobby of mine.

#### cabinetman

· Old School
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I am a math nut. My first degree before going in the army was a B.S Math.

I still read about mathematicians and have always been fascinated with some of the greats. I like to "show off" by telling people what day of the week it would be for a given date. I have it down to about 10 seconds on good days. BTW: it is called the Doomsday Rule. Devised by Jeff Conway.

http://people.cst.cmich.edu/graha1sw/pub/doomsday/Doomsday.html

Math really helps with long range shooting which is a hobby of mine.
That is very cool indeed.

.

· The New Guy
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#### johnnie52

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Math was never one of my better subjects even when I quit driving and began designing machinery. Therefore I generally use the "HURRAY IT FITS!" method. :laughing: After that there is always cubits and spans to fall back on. :laughing::laughing:

#### GeorgeC

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Math was never one of my better subjects even when I quit driving and began designing machinery. Therefore I generally use the "HURRAY IT FITS!" method. :laughing: After that there is always cubits and spans to fall back on. :laughing::laughing:
????????

George

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