Measures of Central Tendency

Mean

 Also known as average; mean is equal to the sum of all the values in a data set divided by the number of values.

Median

To find mode, first we arrange our set of date from smaller to greater.  The median marks the middle mark, the value that in the exact middle.  If you have an odd set of data, just take the two middle values and average them.

Mode

Mode is used for when we want to know the most common category in a chart or data set.

Volume and Surface Area

Volume and Surface Area
Cube

Volume: You have to multiply the height by the width by the length (W*L*H)
Perimeter:  First , we multiply the perimeter by the height. Then, we add the area of the bases (in the case of the cube, there are two bases)

The perimeter is the sum of all sides.

Cylinder



Volume: For the volume we have to multiply Pi by the radius squared by the altitude. (π*r2*a)
Surface Area: You multiply the circumference by the altitude. Then, you add the area of the bases.    (C*A + 2π*r2)


Pyramid


Volume: the volume is the same as the cube, just divided by 3
Surface Area:  the area is the same as the cube with a few differences. When calculating the perimeter times the height divide by two. As the pyramid only has one base, add the area of that one base instead of two.

Cone


Volume: the same as the cylinder, divided by 3
Surface Area:  the same as the cylinder with the same alterations as the pyramid.

Geogebra

Geogebra is an interactive math software for students and teachers to use. Geogebra is free and available for multiple platforms.  Geogebra joins geometry, algebra, and calculus in one single package.  It includes teaching levels from middle schools to high school and it is available in different languages.  Geogebra was created to help students have a better understanding of math.  The idea for Geogebra was conceived in 2001 by Markus Hohenwarter as part of his thesis.  Since then, it has won many awards including:

• MERLOT Classics Award 2013: Multimedia Educational Resource for Learning and Online Teaching (Las Vegas, Nevada, USA)
• NTLC Award 2010: National Technology Leadership Award (Washington D.C., USA)
• Tech Award 2009: Laureat in the Education Category (San Jose, California, USA)

Geogebra works with different types of geometry objects like points and vectors, line and axes, functions, curves, and inequalities. The software can be used for schools or personal learning. Geogebra is able to construct multiple geometric figures and deal with variables for numbers, vectors, and points.

     

For more information visit: Geogebra’s Main Page

divisibility rules

1.    1.    60 by 2 = yes because it ends in zero
2.       49 by 6 = no because it isn’t divisible by 2 or 3
3.       92 by 10 = no because the number doesn’t end in 0
4.       72 by 6 = yes because it is divisible by both 3 and 2
5.       66 by 3 =  yes because the digits add up to a multiple of 3
6.       72 by 3 = yes because the digits add up to a multiple of 3
7.       684 by 9 = yes because the digits add up to a multiple of 9
8.       555 by 3 = yes because the digits add up to a multiple of 3
9.       608 by 2 = yes because the last digit is 8
10.   767 by 9 = no because the digits don’t add up to a multiple of 9
11.   708 by 6 = yes because it is divisible by both 3 and 2
12.   780 by 10 = yes because the last digit ends in 0