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Algebra
absolute value inequalities by Alan Androski

From: Alan Androski <androsa@madison.k12.fl.us>
To: Teacher2Teacher Public Discussion
Date: 1 Nov 00 15:14:30 -0500 (EST)
Subject: math tricks
        
When solving absolute value inequalities: if the absolute value is
greater than a number you must use the conjunction OR, when the
absolute value is less than a number you must use the conjunction AND.
To remember this just remember two words "GOR"-"LAND," which translate
into "G(greater)OR" and "L(less than)AND." When I introduce this
topic I tell students that we are about to enter "GOR-LAND." (no
political implications intended)

equation solving by Greg Smith
From: GREG SMITH <NERD245@AOL.COM>
To: Teacher2Teacher Public Discussion
Date: 14 Jun 99 22:19:15 -0400 (EDT)
Subject: MATH TRICKS FOR PRE-ALGEBRA & ALGEBRA

I use many SMATHism's in class.  Here are several:

In equation solving, I emphasize that we always do "things" in pairs
to maintain equality in mathematices.

In equation solving, I emphasize that we need only perform one
opposite to "get rid of" something.

For equation solving when we want to undo something, we use B. S. well
actually double B. S. to determine where to perform the operation the
Back Side of Both Sides of the equation, or the Bottom Side of Both
Sides of the equation.

When you substitute, always substitute as a quantity.

The verb always becomes the equal sign in equations.

Formulas:
A=(pi)r^2   Apple pies r square
A=(pi)r*r     Apple pies r round
C = (pi)d    Cherry pie delight
I = p r t       I "am" p-r-t             pronounced    I am pretty
rt = d          rt are d                   pronounced    retard

The three s's of equation solving:  Substitute, simplify, solve

I also teach equation solving by using equation solving cycle.  I've
not seen this anywhere else.  An analogy in science would be the water
cycle.  One continuous repetitive cycle.

               <  <   <  <  <  <  <  <  <   <  <  <  <  <  <  <  <  < 
< 
            S      First         symbols of inclusion            Last 
E
            I       Second    exponents                          3rd  
V
           M      Third        multiplication and division   2nd      
L
           P       Fourth     addition and subtraction     First      
O
           L          >  >  >   >  >  >   >   >  >  >  >  >  >  >  > 
>    S
           I
           F
           Y

factoring a trinomial with a lead coefficient by Lyle O'Neal
From: Lyle O'Neal <leoneal@hotmail.com>
To: Teacher2Teacher Public Discussion
Date: 2 Mar 00 14:16:07 -0500 (EST)
Subject: re: math tricks

>The "3R" Method (for factoring a trinomial with a lead coefficient:

1. "R"emove the lead coefficient, but don't throw it away.  Multiply
the constant with the lead coefficent.

2. Factor the remaining trinomial

3. "R"eplace the lead coefficent you removed.  Put it in front of both
x's.

4.  "R"educe!  Reduce the numbers in each set of parenthesis, as you
would a fraction, to lowest terms.

5. Optional - use the FOIL method to check and see that I am right.

*note:  if the three numbers in the trinomial have a common factor it
must be factored out in the beginning for the "3R" method to work.

factoring sum or difference of two cubes by Claudia Carter
One trick that I have created is for factoring sum or difference of two cubes.

   x^3+y^3 =  (x+y)  

then, we SOPPS the binomial to get the trinomial factor. S(quare) O(pposite 
sign) P(roduct) P(lus) S(quare)

   (x+y)(x^2 - xy + y^2)

 -Claudia, for the Teacher2Teacher service

quadratic formula by Beth Phillips
From: Beth <bphillips@mac.com>
To: Teacher2Teacher Public Discussion
Date: 6 Nov 00 23:02:39 -0500 (EST)
Subject: The Quadratic Formula

The quadratic formula can be a tricky equation to memorize when
students first encounter it in Algebra. I rely on a favorite old song
to help my students remember. Try singing the following lyrics to the
tune of "Pop Goes the Weasel"

x is equal to negative b
plus or minus the square root
of b squared minus 4ac
ALL over 2a

Twelve years ago I was taught this song, and I STILL hear the tune
every time I use the quadratic formula!

quadratic formula by Kay Wilson
From: Kay <kwilson@putnamcityschools.ore>
To: Teacher2Teacher Public Discussion
Date: 11 Jan 00 15:22:38 -0500 (EST)
Subject: Remember the quadratic formula
        
To teach students to remember the quadratic formula, teach them to
sing it to the tune of "PoP! Goes the Weasel"

"X equals a negative b
 Plus or Minus the square root,
 Of b squared minus four a c
 All over 2 a"

quadratic formula by Lyle O'Neal
From: Lyle O'Neal <leoneal@hotmail.com>
To: Teacher2Teacher Public Discussion
Date: 2 Mar 00 14:16:07 -0500 (EST)
Subject: re: math tricks

>Quadratic Formula (sung to the tune of pop-goes-the-weasle:

"x is equal to negative b, plus or minus the square root, of b squared
minus 4ac, all over 2a"

solving inequalities involving absolute value by Greg Smith
From: GREG SMITH <NERD245@AOL.COM>
To: Teacher2Teacher Public Discussion
Date: 14 Jun 99 22:19:15 -0400 (EDT)
Subject: MATH TRICKS FOR PRE-ALGEBRA & ALGEBRA

When solving inequalities involving absolute value, the students and I
have developed the following phrases to determine whether the two
solution sets contain the word "and" or "or" in them: 
|x+5|> 6   "great OR"
|x - 2| < 3  "less th AND"
|x + 2| = 4 "equat OR"


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Arithmetic
9 times table by Alicia
From: Alicia <alicia_1313@hotmail.com>
To: Teacher2Teacher Public Discussion
Date: 29 Nov 00 13:36:47 -0500 (EST)
Subject: Re: 9 times table and 11 times table tricks

Another trick for the 9 times table up to 9x10 is to write the numbers
0-9 down the left hand side:

    0
    1
    2
    3
    4
    5
    6
    7
    8
    9

Then, repeat the process of writing the numbers 0-9, this time going
UP the right side:

    09
    18
    27
    36
    45
    54
    63
    72
    81
    90

Now you have your 9's times table:


    9 x 1 = 09
    9 x 2 = 18
    9 x 3 = 27
    9 x 4 = 36
    9 x 5 = 45
    9 x 6 = 54
    9 x 7 = 63
    9 x 8 = 72
    9 x 9 = 81
    9 x 10 = 90

Have fun!

9 times table by Jody Underwood
From: Jody Underwood <jody@mathforum.org>
To: Teacher2Teacher Public Discussion
Date: 17 Nov 00 10:56:56 -0500 (EST)
Subject: 9 times table and 11 times table tricks

I love math tricks.  I remember learning these in the 5th grade from
my student teacher, Miss Ansell.

9 times table:

(This is hard to explain in words, but I'll try.)  
Open both your hands and face them to you.  Put down your left thumb. 
This represents 9 x 1 = 9.  (Notice there are 9 fingers in one
"group".  The groups will become more obvious in a minute.)

Lift your thumb, and put down the pointer finger of your left hand. 
there's 1 finger on the left of the "down" finger, and 8 on the right.
That represents 18, or 9 x 2.  The 2 comes from the second finger.

Raise all your fingers again, and put down the middle finger of your
left hand.  This gives you 2 fingers to the left of the down (third)
finger, and 7 to the right of it.  9 x 3 = 27.  

Get it?  It only works up until 9 x 10 = 90.  I've shared this with
adults who say they're lousy at their multiplication tables, and they
are upset they didn't learn it in the 5th grade, too!

-Jody

11 (multiplication by) by Noorali Jiwaji
From: Noorali Jiwaji <njiwaji@hotmail.com>
To: Teacher2Teacher Public Discussion
Date: 4 Nov 00 21:51:28 -0500 (EST)
Subject: Multiplying by 11

MULTIPLICATION BY 11

For 2 digit numbers: Add the two digits and keep the answer in between
the two digits.  If the addition comes to more than 10 then carry over
and add to the left hand digit.
E.g.  68 x 11
    = 6 (6+8)  8
    = 6  (14)  8
    =6+1  (4)  8
    = 7    4   8
    = 748

For more than two digits: Keep the extreme digits on their respective
extreme sides, then pair off digits starting from the left and add the
pairs from the right keeping the answer in their respective positions,
carrying over if required. 
E.g. 7964 x 11
   = 7 (7+9) (9+6)  (6+4)  4  
   = 7  (16)  (15)   (10)  4
   = 7  (16) (15+1)   (0)  4
   = 7  (16)  (16)     0   4
   = 7 (16+1)  (6)     0   4
   = 7  (17)    6      0   4
   =7+1 (7)     6      0   4
   = 8   7      6      0   4
   = 87604.

Quite amazing and satisfying, especially for large numbers!

Dr. Noorali Jiwaji

11 times table by Jody Underwood
From: Jody Underwood <jody@mathforum.org>
To: Teacher2Teacher Public Discussion
Date: 17 Nov 00 10:56:56 -0500 (EST)
Subject: 9 times table and 11 times table tricks

Here's one for the 11 times table:

This only works (simply) for 11 times two-digit numbers.  Let's say
you want to multiply 11 by 23.  Write down the 23, but with a space
between the two numbers:

  2 3

Add them up and put that number in the middle.

  253

That's 11 x 23.  If you have a carry, you have to add it into the left
number, so it's not as clean as you would want, but it's still cute
and fun for kids.  You can extend this for 3 and more digit numbers,
but carry overs get more complicated.  I found it a lot of fun as a
kid, and continued to play with it to extend it as far as I could.

-Jody

change a mixed numeral to an improper fraction by Greg Smith
From: GREG SMITH <NERD245@AOL.COM>
To: Teacher2Teacher Public Discussion
Date: 14 Jun 99 22:19:15 -0400 (EDT)
Subject: MATH TRICKS FOR PRE-ALGEBRA & ALGEBRA

In class to change a mixed numeral to an improper fraction, I use the
chant:  the bottom times the side plus the top.

divisibility by Brenda Barrow
From: Brenda Barrow <bpbarrow@juno.com>
To: Teacher2Teacher Public Discussion
Date: 6 Jul 00 09:15:34 -0400 (EDT)
Subject: Re: math tricks needed in Southern California

I know you needed some math tricks before now but maybe you can use
these for the future.  To find out if a number is divisible by 9 you
can add the digits of the number and if you get a multiple of 9 it is
divisible by 9.  As a matter of fact if you keep adding the digits of
the numbers you get you will eventually get to a sum of 9.  Ex. 459
Add the digits.   4+5+9 = 18  18 is a multiple of 9, so 458 is
divisible by 9.  If you add the 1 and the 8 in 18 you get 9.  This
also works for numbers that are divisible by 3 or 6 except you can get
a sum of 3, 6 or 9.  Of course the number has to be an even number in
order to be divisible by 6.  When you actually work with students have
them make these discoveries instead of just telling them.  It is very
exciting for them and when they discover it they usually remember it. 
Also if students have a large number that they want to know if it is
divisible by 9 they can try finding sums of 9 within the number and
they will know it is divisible by 9.  Ex. Is 853,164 divisible by 9?  
A student can see that 5+4 =9 and 6+3=9 and 8+1=9, so 853,164 must be
divisible by 9.  It's also divisible by 3 and 6.  If I switched the
last 3 digits around to make them 641 instead of 164 the number would
no longer be divisible by 6 because all numbers that are divisible by
6 must be even numbers. That is not to say that all even numbers are
divisible by 6, but that all numbers that are divisible by 6 must be
even.  This kind of thinking helps students develop number sense.  I
am a math resource teacher and math lead teacher at Monroe Elementary
School in Norfolk, Va.  Since I am a resource teacher I have the
opportunity to work with 3rd, 4th and 5th graders most of the time.  I
do a lot of motivational things in math for the whole school so that
our students feel that they are immersed in math.  We are math lovers
and not math phobics.  Are you planning to teach?  If I can be of
assistance let me know.  I wish you the best.   Brenda ( < : }  

division by Greg Smith
From: GREG SMITH <NERD245@AOL.COM>
To: Teacher2Teacher Public Discussion
Date: 14 Jun 99 22:19:15 -0400 (EDT)
Subject: MATH TRICKS FOR PRE-ALGEBRA & ALGEBRA

For division, I tell the students to put the "top-in's" and
"left-overs" inside the refrigerator i.e., whatever is on top of the
fraction or whatever is over on the left of the division sign is
placed inside the long division symbol (dividend).  This strategy also
works with the calculator.

equivalent fractions by Robert Mehigan
From: rob <robert.mehigan@cathedral.qld.au/>
To: Teacher2Teacher Public Discussion
Date: 17 Aug 00 02:35:14 -0400 (EDT)
Subject: Re: math tricks needed in Southern California


A student only today told me of a maths trick his Dad had passed on to
him.  (Good on you,parents!)

Re:  Equivalent fractions  1/2  =  3/x

                       Say "3 divided by 1, times 2 = x" 
 
     Simple and end of story.  There is no playing around with guess
and check methods, nor the hassle of setting up cross multiplication,
nor more formal multiplying both sides.

                   So what about x/2= 4/8 ?  
Well I figured out what to do......

                        Say "4 times 2, divided by 8 = x"

The methods are a kind of shorthand that has to be learned, which may
be ideal for the students who are weaker in conceptualising the more
formal methods.  Hope this helps.

fraction to a decimal by Cheryl Ireland
From: Cheryl Ireland <irelandcheryl@hotmail.com>
To: Teacher2Teacher Public Discussion
Date: 13 Oct 00 12:45:34 -0400 (EDT)
Subject: changing a fraction to a decimal

When teaching students to change a fraction, 3/4 to a decimal, I tell
them to associate the denominator with "dog" and the numerator with
"Nancy."  Denominator dog stays outside the house (the bracket) and
Numerator Nancy goes inside the house.

mixed numbers to improper fractions by Amy Standring
From: Amy Standring <amy_lyn_1025>
To: Teacher2Teacher Public Discussion
Date: 16 Oct 00 18:37:41 -0400 (EDT)
Subject: A Trick for changing MIXED NUMBERS to fractions

        To teach changing mixed numbers to improper fractions, I use the
"LOOP" idea.  The students make a "loop" by multiplying the whole
number by the denominator, adding it to the numerator and placing all
that over the denominator again.  I use an arrow going around the
mixed number to illustrate the idea.  When i tell the kids to "make
their loop"  they know exactly what to do!! (Much more so than if i
said "change to an improper fraction...")

percentage of change by Kimberley Girard
You might be interested in a mnemonic device developed by my freshmen
students for remembering how to do this type. They used "(new - old)/ old".
This gives a decimal form which can easily be written as a percentage.

Old refers to the original price (in your problem); new refers to the current
price. A positive answer means there was a percentage of increase, a negative 
means a percentage of decrease.

 -Kimberley, for the T2T service

squares of numbers ending with the digit 5 by Anjali Poonia
From: anjali <anjalipoonia@hotmail.com>
To: Teacher2Teacher Public Discussion
Date: 20 Oct 00 12:25:53 -0400 (EDT)
Subject: SQUARES OF NUMBERS ENDING WITH DIGIT 5

        
    THIS IS AN INTERESTING TRICK TO FIND SQUARES OF NUMBERS ENDING
WITH THE DIGIT 5
     
         e.g.  25*25= 
first digit(first digit+1)second digit*second digit
=2(2+1)25=2(3)25=625.
  This is an example of two digit number.
  Here we have just miltiplied the first digit with the first digit
added to one.Units &tens place will always be taken by the digit 25. 
The result of the product of the tens digit  &its successor will
always take hundreds or thousands place.Similarly we can find squares
of numbers having more than two digits,but the thing to remember is
that leaving the number in the units place the rest of the number is
considered as a single number.Here too the units &the tens place will
betaken by the digit 25 &the resultant product will take hundreds or
thousands place depending on how big is the digit.
   Another e.g. with three digit 325.square of 325 will be
   325*325=32(32+1)25=32(33)25=(1056)25=105625.
   6125*6125=612(612+1)25=?

what to do with a zero in a fraction by Alan Androski
From: Alan Androski <androsa@madison.k12.fl.us>
To: Teacher2Teacher Public Discussion
Date: 1 Nov 00 15:14:30 -0500 (EST)
Subject: math tricks

A great trick that a student taught me for remembering what to do with
a zero in a fraction- it's called the happy and the sad man.  Imagine
two stick men created with a zero, a fraction bar and the number
symbol.

first one (drawing below): this is the happy man because he is
standing upright.  He is also happy because he can divide and get an
answer.  It is equal to zero.

O
-
#

second one (drawing below): this is the sad man because he is upside-
down.  He is also sad because he cannot divide.  It is not equal to
anything, it is undefined.

#
-
O


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Geometry
isosceles triangles by Dr. A.V. Manohara
From: Dr.A.V.Manohara sharma <vidyamanohar@yahoo.com>
To: Teacher2Teacher Public Discussion
Date: 9 Aug 99 12:46:47 -0400 (EDT)
Subject: coordinate geometry

        
to see which triangle the three given lines form

observe whether the slopes of the lines are 

like m, 1/m and 1    OR m, 1/m and -1

then the triangle should be isosceles

ex.


the lines 2x+3y+6=0, 3x+2y-1=0 and x-y+4=0 for and isosceles triangle

as the slopes here are -2/3 , -3/2 and 1.

measure of the special segments of a circle by Deborah
From: deborah <antrimb@bellsouth.com>
To: Teacher2Teacher Public Discussion
Date: 1 Jul 00 01:03:14 -0400 (EDT)
Subject: Re: Circle theorems


  To teach finding the measure of the special segments of a circle we
have a song to the tune of "Row, row your boat" It goes like this:

          Chord is part*part = part *part
         Secant is outside all = outside all
          
          Chord is part * part = part * part (chorus)
        Tangent squared = secant segment * outside
I can usually teach this in a day and the students know how to apply
the song to problems by the end of the class period.  I demonstrate
the problems along with the song and then the class sings and
demonstrates.

supplementary and complimentary angles by Lynne Jacobsen
From: Lynne <ljacobse@spsflames.k12.wi.us>
To: Teacher2Teacher Public Discussion
Date: 2 Sep 00 13:01:18 -0400 (EDT)
Subject: Supplementary and Complimentary Angles

I teach middle school students.  My students know that supplementary
and complimentary angles are angles that equal 90 degrees and 180
degrees, but they get confused as to which is which.  They also know
that 90 degree angles are right angles.  So I tell them that a
compliment is the right thing to do, and right angles equal 90
degrees, therefore complimentary angles are two angles that equal 90
degrees.  Then they know that 180 degrees is the other one,
supplementary.  

supplementary and complimentary angles by Mary MacNeil
From: Mary MacNeil <MMacNeil@malden.mec.edu>
To: Teacher2Teacher Public Discussion
Date: 9 Nov 00 18:55:07 -0500 (EST)
Subject: Re: Supplementary and Complimentary Angles

"Complementary" -  early in the alphabet, so = 90
degrees.
"Supplementary" -  later in the alphabet, so = 180
degrees.

My middle school students show me 90 degrees with their arms
(straight up, straight out - I'm fussy), then estimate various acute
and obtuse angles with their arms.  It's fun to do quickly - they look
like they're going to fly.   This also helps them to choose the
appropriate scale on the protractor.   Simple kinesthetic.

triangle names by Lynn Greenwade and students

From: Lynn Greenwade
To: Teacher2Teacher 
Date: Oct 23, 2006 at 16:19:27
Subject: triangle names
My adult GED students jumped on the mnemonic PEMDAS, and they want one
for remembering the names of triangles.  In particular, isosceles and
scalene give them trouble. Here is what we came up with:

Equilateral triangles have 3 sides and 3 angles equal.
Isosceles triangles have 2 sides and 2 angles equal.
Scalene triangles have 0 sides and 0 angles equal.

So, to remember them in that order, EIS, "Eat ice slowly".

two given lines cut the coordinate axes in four concyclic points or not by Dr. A.V. Manohara
From: Dr.A.V.Manohara sharma <vidyamanohar@yahoo.com>
To: Teacher2Teacher Public Discussion
Date: 9 Aug 99 12:53:33 -0400 (EDT)
Subject: coordinate geometry
    
to see whether the two given lines cut the coordinate axes in four
concyclic points or not 

just see whether the product of coefficients of x in both the
equations is equal to that of coefficients of y.

if the given lines are ax+by+c=0 and bx+ay+d=0 
they cut the axes in concyclic points.


[top]

Metric Measurement
metric conversions by Errol LaGuerre
From: Errol LaGuerre <broErrol@aol.com>
To: Teacher2Teacher Public Discussion
Date: 21 Jun 99 01:45:26 -0400 (EDT)
Subject: Conversions in metric


my         milli
cat        centi
died       deci
unusually  unit
drinking   deca
hot        hecta
ketchup    kilo


e.g. Convert 10 decameters to centimeters. 
Set up the columns as shown below so that the ones column comes under
deca. Move the decimal point to the right of the column with centi.
Add zeros until you are under centimeters. That is your answer.

kilo   hecta   deca   unit   deci   centi   milli
         1      0

kilo   hecta   deca   unit   deci   centi   milli
         1      0      0      0      0

i.e. 10 dam = 10 000 cm

Try, as an exercise, to convert from small units to larger units. 

metric conversions by Jim Wenk
From: Jim Wenk <Jimwenk@home.com>
To: Teacher2Teacher Public Discussion
Date: 26 Jul 00 02:26:04 -0400 (EDT)
Subject: Re: Conversions in metric

Another play on the metric conversions is:
"King Henry Died Monday Drinking Chocolate Milk"

Km   Hm  Dam   M   Dm   Cm   Mm

To convert...

3.75 Hm = ______ Cm

It's 4 jumps to the right from Hm to Cm, simply move the decimal
4 jumps to the right.

3.75 Hm = 37,500. Cm

To convert...

0.59 Dm = _______ Hm

It's 3 jumps to the left from Dm to Hm, simply move the decimal
3 jumps to the left.

0.59 Dm = 0.00059 Hm

metric systems by Dawn
From: Dawn <slugtop@hotmail.com>
To: Teacher2Teacher Public Discussion
Date: 13 Nov 00 17:52:43 -0500 (EST)
Subject: metric conversion

        This is just another way to remember the order to convert in the
metric systems, and it gets away from just using meters.

Kahn's          kilo
Hot             hecto
Dogs            deca
Uses            units (meter, liter, or grams)
Dead            deci
Cow             centi
Meat            milli


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Special Numbers
e to 15 decimal places by Matt Collins
From: Matt Collins <matty7737@netzero.net>
To: Teacher2Teacher Public Discussion
Date: 2 Aug 00 10:50:09 -0400 (EDT)
Subject: Remembering e to 15 decimal places

        Here's a cool way to remember e to 15 decimal places:
e=2.718281828459045...

Andrew Jackson was the 7th president, elected in 1828 to two terms.
Then tack on the 45-90-45 right triangle.

Feel free to share with history teachers in your school.

Matt

feet in a mile by Bob Stanarrow
From: Bob Stanarrow <Straitfromtheheart@aol.com>
To: Teacher2Teacher Public Discussion
Date: 7 Mar 01 17:38:50 -0500 (EST)
Subject: How to remember how many feet in a mile

        I figured out a way to remember how many feet are in a mile.

Just say to yourself 5 tomatoes. Really there are 5,280 feet in a
mile, so you can remember that by saying 5 tomatoes.

  5    to   mat  oes
( 5 ) ( 2 )( 8 )( 0 )

pi - first eight digits of by Alan Androski
From: Alan Androski <androsa@madison.k12.fl.us>
To: Teacher2Teacher Public Discussion
Date: 1 Nov 00 15:14:30 -0500 (EST)
Subject: math tricks

To get the first eight digits of pi, count the number of letters in
each word of this phrase:  May(3) I(1) have(4) a(1) large(5)
container(9) of(2) coffee(6)?


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Statistics
Central tendencies by Nancy Patrizio

From: Nancy <Patrizio@ix.netcom.com>
To: Teacher2Teacher Public Discussion
Date: 3 Mar 00 22:11:53 -0500 (EST)
Subject: Central tendencies

To help my middle grade students remember range, mean, median and
mode- Range - I tell the them to think of a gas range that has high
and low temperatures. This helps them to remember to subtract the
lowest from the highest number. Mean - the "a" in mean stands for the
average or my students like to think of it as "the mean teacher gives
you your average of your grades"!. Median - think "mid" - the number
or numbers in the middle. Mode - think "most" - the number or numbers
that occur the most. It sounds so simple but it works!  
is/of works wonders when working with percentages 

When multiplying or dividing numbers by 10, 100, 1000,...,use MR
DL(Mister Doll) ;when multiplying, move the decimal to the right; when
dividing, move the decimal to the left.
When multiplying or dividing numbers by.1, .01, .001,...,use DR
ML(Doctor Mole) ;when multiplying, move the decimal to the left; when
dividing, move the decimal to the right.


[top]

Trigonometry
definition of a logarithm by Marielouise Derwent

Date: Oct 23, 1998 at 15:04:14
Subject: Re: Math Tricks

One of the ideas that I have used for a long time is for the definition of a logarithm:

If     (base)^(Exponent) = (Number)  
then,  log (Number) to the (base) = Exponent
       b^E = N,  
               if  log N to the b = E.

When doing transformations of functions remember:  RST!  Do your Reflections
first, then your Size changes of compressing or stretching and then your
Translations of sliding up, down, right and left.

This helps students when they are trying to decide what the equation of a
transformation is when looking at a graph. They then do the RST in reverse
order: Translate first, then change sizes and then reflect over x-axis or y-
axis.

 -Marielouise, for the Teacher2Teacher service

positive trig. values in the quadrants by Maree McCarthy

From: Maree <mmccarthy@glenstal.org>
To: Teacher2Teacher Public Discussion
Date: 25 Oct 00 10:07:03 -0400 (EDT)
Subject: Trigonometry

        For the positive trig. values in the quadrants, All Sexy Tom Cats
works great - if you do not mind the giggles! 

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