# Math tricks



## nealtw (Nov 20, 2015)

multiplying
[ame]https://www.youtube.com/watch?v=_AJvshZmYPs[/ame]


----------



## bud16415 (Nov 20, 2015)

Thats crazy.


----------



## Chris (Nov 21, 2015)

Interesting.

If you ever need to calc asphalt. It is square footage x depth in inches x 
.006 = tons


----------



## Chris (Nov 21, 2015)

I'm just rambling here.

Find the volume of a cylinder.

Pie x R squared x length

If calced in feet you can divide by 27 to get cubic yard.


----------



## frodo (Nov 21, 2015)

take your tape measure, pull it out,  fold the tape back, put the end of the tape on  the  year  215 

hold them together.  look at your age, the year your born is on the other tape


----------



## havasu (Nov 21, 2015)

I have a similar one. Get a tape measure, fold it in half. Fold it once again. Turn the tape over, and you will find the day you were born on your birth certificate.


----------



## Chris (Nov 24, 2015)

Do any of you guys use the 3,4,5 trick to make sure your walls are square?


----------



## nealtw (Nov 24, 2015)

Yes, all the time.,


----------



## bud16415 (Nov 24, 2015)

Did it just the other day. Some times I do the 1x1x1.414 also.


----------



## Chris (Nov 24, 2015)

I don't know that one


----------



## bud16415 (Nov 24, 2015)

Any time you have a square across the corners is 1.414x the side. So if you are making a 10x10 box across the corners is 14.14.

 1.414 is a good number to remember same as 3.14


----------



## nealtw (Nov 24, 2015)

bud16415 said:


> Any time you have a square across the corners is 1.414x the side. So if you are making a 10x10 box across the corners is 14.14.
> 
> 1.414 is a good number to remember same as 3.14



both measurements corner to corner have to be same, no math.


----------



## bud16415 (Nov 24, 2015)

nealtw said:


> both measurements corner to corner have to be same, no math.



You are doing math though and more work. Say you measure corner to corner and you get 10 7, 11/16 one way and the other way you get 10 6, 5/16 the other way. You have to then add the two and divide by 2 or take the difference in the two divide that by 2 and add half to the smaller one. Now what you could do and what most people do is bump the one in about what you think half is and then measure again both ways and you are closer and then repeat over and over until you say close enough. Sometimes you are up and down a ladder doing this. One multiplication and you can get it right the first time.


----------



## nealtw (Nov 24, 2015)

We square walls on the floor and apply plywood there. The wall starts with the bottom plate nailed to the floor on on the line where it will be stude. The other lines on the floor give you a reference for straight sides so squaring is double checking and when out hardly ever more than 1/8 inch. But if the two plates are different length, that mistake is cought early.
Stick built walls are not squared, the corners are plumbed and the center is eyed straight or stringline straight


----------



## frodo (Nov 28, 2015)

just call information,  1 411  lol

use the 345 all the time..upside down,  

mark the concrete ceiling then pop a chalk line when laying out for pipe hanger anchors 

use my tape all the time to subtrack and add,

just fold it over and count back,,,it is quicker than a calculater


----------

