Area and volume of geometric shapes

Hi all,

these days we have been working in class with surface area and volume of some geometric shapes. I leave you here some links to go over the most important ones: Platonic solids (tetrahedron, cube, octahedron, dodecahedron, icosahedron), PyramidPrismCylindercone and sphere.

Remember that you have to present by the end of this week your work including:
1. Name of your shape.
2. Description.
3. Picture.
4. Net (See website to get some ideas).
5. Surface area and volume.
6. Examples in real life.
(Deadline: friday, 30th of november)

If you want to practice or get some ideas or pictures, you can find more exercises here:

And here I post as well the summary I promised... Download file.

Take care,


Sieve of Eratosthenes

The Sieve of Eratosthenes is an ancient method for finding all primes numbers up to a specified number.

It was created by Eratosthenes (275-194 B.C., Greece), an ancient Greek mathematician. Just as a sieve is a strainer for draining spaghetti,  Eratosthenes's sieve drains out composite numbers and leaves prime numbers behind. The numbers from 1 to 100 are listed in a table. We will  use The Sieve of Eratosthenes to find all primes up to the number 100 by following the directions below.

  1. Cross out 1 since it is not prime.
  2. Circle 2 because it is the smallest prime number. Cross out every multiple of 2.
  3. Circle the next open number, 3. Now cross out every multiple of 3.
  4. Circle the next open number, 5. Now cross out every multiple of 5.
  5. Circle the next open number, 7. Now cross out every multiple of 7.
  6. Continue this process until all numbers in the table have been circled or crossed out.
You have just circled all the prime numbers from 1 to 100!

Download presentation

Questions (to be answered as a comment):

1. How many prime numbers are there from 1 to 100?
2. List all prime numbers from 1 to 100.
3. Which number is the only even prime number?
4. An emirp (prime spelled backwards) is a prime that gives you a different prime when its digits are reversed. For example, 13 and 31 are emirps. List all emirps between 1 

Enjoy it.


Human Rights

Human Rights Day is celebrated annually across the world on 10 December. United Nations representatives from all regions of the world formally adopted the Universal Declaration of Human Rights on December 10, 1948. It is the most universal human rights document in existence, delineating the thirty fundamental rights that form the basis for a democratic society. But...Do you think the thirty human rights are respected nowadays?

Many people know something about their rights. Generally they know they have the right to food and a safe place to stay. They know they have a right to be paid for the work they do. But there are many other rights. Do you know all of them? Here you have thirty videos of the thirty human rights. 



Money, Money, Money...

When you borrow money from a bank, you pay interest. Interest a fee charged for borrowing the money, it is a percentage charged on the principle amount for a period of a year - usually.
If you want to know how much interest you will earn on your investment or if you want to know how much you will pay above the cost of the principal amount on a loan or mortgage, you will need to understand how compound interest works (See video).
Compound interest is paid on the original principal and on the accumulated past interest.
Practice doing the activity here.
Take care.


Exam Units 1 and 2

Dear all,

Our first exam is coming... To help you here you have some examples of text commentary. One is about The Declaration of Independence and the other one is about a text writed by Montesquieu.

Furthermore, this is the second part of the commentaries.

And last but not least, this is the list of concepts for the exam:

Natural increase; Guilds; Estates; Bourgeoisie; Absolute monarchy; Enlightened despotism; Enlightenment; John Locke; Voltarie; Rousseau; Montesquieu.