Mnemonics for math

[Kruegs1982]

This thread is in response to the new thread started in another forum. I thought it might be helpful to share the mnemonic devices we all use in our math classes.

One that pops into my head is PEMDAS (order of operations: Parenthesis, exponents, multiply, divide, add, subtract)

http://members.tripod.com/~ForgetKnot/math.html

[teacher]

For trig: All Students Take Crack (candy, calculus..)=In the first quadrant All (everything) is positive. In the second quadrant Sin is positive, in the third quadrant Tan is positive, in the fourth quadrant Cos is positive.

More Trig: SOHCAHTOA-->
sin=opp/hyp
Cos=Adj/hyp
Tan=Opp/Adj

Another trig: S goes with C and C goes with S:
cos is the reciprocal of sec and csc is the reciprocle of sin

For parabolas: +x^2 is positive=a smiley face shape. -x^2 is negative=in the shape of a frown

Not really a mnemonic but helps explain negative times/divide negative=positive..... :
I am not not going to the store=I am going to the store (negative times negative=positive)
I am not yes going to the store= I am not going to the store (negative times positive=negative)
I am yes not going to the store=I am not going to the store (positive times negative=negative)
I am yes yes going to the store (positive times positive=positive)

< is less than the < is in the shape of a slanted L for Less than

5< 6 mouth is always open to the bigger number

Octagon has eight sides like an octopus

((Number of sides in a polygon)-2) times 180 equals number of degrees in the figure
If you divide this number by the actual number of sides of the polygon you get the degrees in each angle

please exuse my dead aunt sally=PEMDAS

[ddehaan]

This is in response to about mnemonics. Although this is not a mnemonic, this is a way to determine how many degrees are in a polygon without having to remember an equation. All you have to do is tell the student to see how many triangles they can draw in the polygon from the polygons vertices. IN other words, try to make triangles in the polygon. Each triangle is 180 degrees. So if they can make 2 triangles, the polygon's angles equals 360 degrees. If they can make 4 triangles (4x 180) the polygon's angles equals 720 degrees, etc. It sure is better than making them learn a formula!

You can make 4 triangles in a hexagon: so 4x180 =720 degrees
You can make 3 triangels in a pentagon: so 3 x 180 = 540 degrees

To find the degree of each angle, divide by answer by the number of sides!


You can also check out www.madaboutscience.org's website and check out the mnemonics for science and math. Math is due out in January, 2008.

[darlyne]

Determining how many degrees are in a polygon

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This is in response to about mnemonics. Although this is not a mnemonic, this is a way to determine how many degrees are in a polygon without having to remember an equation.

All you have to do is tell the student to see how many triangles they can draw in the polygon from the polygons vertices. IN other words, try to make triangles in the polygon. Each triangle is 180 degrees. So if they can make 2 triangles, the polygon's angles equals 360 degrees. If they can make 4 triangles (4x 180) the polygon's angles equals 720 degrees, etc. It sure is better than making them learn a formula!

You can make 4 triangles in a hexagon: so 4x180 =720 degrees :rolleyes:
You can make 3 triangels in a pentagon: so 3 x 180 = 540 degrees :D

To find the degree of each angle, divide by answer by the number of sides!:eek:


You can also check out www.madaboutscience.org's website and check out the mnemonics for science and math. Math is due out in January, 2008.

[Unregistered]

one of my favorites is for remembering which is x= and which is y= for horizontal and vertical line equations. Tell them to just remember "The line you pass through is the line that names you" So if the line passes through the x-axis, it will have an equation of x=

also, sing the quadratic formula to the tune of Frere Jacques..."negative b, negative b, plus or minus square root, plus or minus square root, b squared minus 4ac, b squared minus 4ac, all over 2a, all over 2a"

...btw, I'm a little appalled by the all students take crack...my lord, people, we are role models here!

[Unregistered]

I use a couple....
MADS...Multiplying with like bases, Add the exponents; Dividing with like bases, Subtract the exponents; this acronym also works with logs (when Muliplying, separate by Adding; when Dividing, separate by Subtracting

When graphing vertical and horizontal lines, to remember that y= goes with horitontal and x= goes with vertical, I use the words HeY and VeX.

You can also sing "Pop Goes the Weasel" for the Quadratic Formula.

Complimentary goes with 90, Suplimentary goes with 180 because C comes before S in the alphabet and 90 comes before 180 numerically!

That's all I can think of at the moment!!!

[Unregistered]

I use "y^2 = 4 powerful exorcists" to remember y^2 = 4px, the standard form of a quadratic equation.

For the equation of a square, I have (axe-head)squished + (you - king)squished = our square.


For the inverse trig identities, I use "cotton sisks in seconds." (cot is inverse of tan, csc is inverse of sin, sec is inverse of cos.)

For the negative angle identities, I use "cosine is positively crazy, but sine and tangent are negative." since cos(-x) = cos x, whereas the output is negative for tangent and sine functions with negative angles. I was inspired by the mnemonic "cosine is crazy, sine is sane."

[rah07]

Hi,

This forum contains very good information. I really liked this topic. It provides lot of knowledge to students.

Roh

[shubh]

There are three basic types of mnemonic strategies:

* Keyword - A keyword is a familiar word that sounds similar to the word or idea being taught. Keywords are generally used with an illustration of some type.
# Pegword - Pegwords refer to a set of rhyming words that are used to represent numbers. For example, the pegword for "one" is "bun." Pegwords are used to help students remember information involving numbers or other information in a particular order.
# Letter - Letter strategies include acronyms and acrostics (or sentence mnemonics). For example, the acronym HOMES can be used to help students remember the names of the Great Lakes (Huron, Ontario, etc.).