Percentage increase and decrease

'Percent' means 'out of 100'. A percentage is a fraction of 100. 

In some questions you are given the cost price and the selling prices and have to find the percentage increase or decrease. This means you need to find one amount as a percentage of another. You form a fraction from the two amounts and multiply this by 100. Have a look at this websiteand try this activity after reading. Check if you understood doing this test.

To study in depth, have a look here. And check what you learned with this test.

And last but not least, see this problems here to finish your study.

Take care.


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.



Texts about European Revolutions

Here you have the texts about the Unit 1. Choose one about the American Revolution and other about the French Revolution.


Writing a horror story

The Social Science teacher says that reading is a pleasure. I say...

Write, what a pleasure!!!

This year we will write a horror story to celebrate Halloween. Here you have the steps you have to follow to be successful.

And remember, you shouldn't write more than 200 words

Nine steps to write a horror story
1. Get an idea. How bad is it when a horror story has no great idea to get it started? To get these ideas, try to think of them just as you're starting to drift off to sleep. Try to think of the things that you wouldn't want coming out at you from those shadows, and then begin to think of what might happen if they did. For example: "Oh my gosh! I would not want an evil monster to slowly open the door to my room trying to make me like them! That would be horrible!" could be something you'd be thinking about.1
2. Take care of the details. This is just good, general advice for any story: you - need - details! What good are your setting, your characters, minor and biggest plot events if you don't have the details to go with them?
3. Plan it out. It's a good idea to write out what will happen in the story, in point form, before you actually write out your story. You can use the point form notes as a guide; they'll keep you from getting lost or going around in circles. Don't be too elaborate in your point form notes; you just want the big things that are going to happen and the order in which they go.
4. Think of an exciting first sentence. Nothing is better than to start a story with an exciting, unexpected sentence then keep the detail and excitement going. This will catch the readers eye and encourage them to keep reading.
5.. Just write. Put pen to paper and write, write, write. Follow your guidelines so that you don't go in circles and lose the reader. Be sure not to use too much mystery, if you're inclined to; your reader needs to know what's happening in order to be scared, after all.
6..Eerie settings. Some locations are better suited for a horror story than others. Places related to death make a great deal of difference in the story. For example you could have your story set in a graveyard, and old dilapidated mansion or a castle.
7..Add the horror. Ask people what scares them the most, then think of something you're afraid of, then think of something genuinely scary, toss it into the pot and bingo! You have horror.
8. End with a bang. A very scary bang. Try not to make the ending happy. It is horror, after all.
9..Rewrite. Go through your story, edit it, rewrite what parts look like they could be better said, and then get your friends and acquaintances to read the story too! They are usually better than you at picking up mistakes you've made up.


Read, what a pleasure!

Here you have the list of books related to Contemporary History.

You have to choose one of them, read it, and ask for the work. I have almost all.

Download the list here

French Revolution Report

Do you remember the freaky guy from whom we watched a video about American Revolution?

Here he is!


Covent Garden

A lot of tourists go to Covent Garden every day. In this market we find ...

Look this video and finish the story.


Hi everybody!

We are beginning a new year in the European Section, our fourth one. It’s time to welcome all the new people who are going to share our project, students (too many to mention each one) and teachers (Virginia, Almudena, Marta and Julio) and it’s also time to thank the people who have been with us in previous years but  they have left the Section for different reasons, the students again and  teachers such as Ana Esther, Flor or Ingrid.

This year, due to the budget cuts we won’t have a very important figure in this project, the foreign language  assistant, so we want to thank Megan and Kate, our excellent assistants these last years,  their work with us.

We hope all of us enjoy a lot and have a very successful year in spite of the difficulties.


Percent increase and decrease

Percent increase is when you find a given percent of an amount and then add it to it.
Percent decrease is when you find a given percent of an amount and subtract it from it.

 One really important thing to remember about percent increase and decrease is that percent is always based on something, it doesn't stand alone, there is always something that it is "of" and with percent increase and decrease problems that is always the ORIGINAL amount.

There are three kind of percent increase and decrease problems and a good first step towards solving a problem is to decide which of them it is:
 1.Original amount, percent known, you want to find the new amount.
 If cost of life is running at 3%, how much would you need to live a year if your current expenditure is $920 per month?
 2.Original amount known, new amount known, you want to find out what percent the increase or decrease is. 
The value of Spain exports to Germany increased from €1480 million in 1987 to €2768 million in 1988. What was the percentage increase?
3.New amount known, percent known, you want to find the original amount.
 An item originally costing $20 is on a 10% off sale. What is the sale price? 

Solve the problems in a paper and write the answer as a comment.

See more information and examples here and here.




Did you know that if rich countries invested just 0.7 % of their GNI we could end up with extreme poverty? If you want to know more about that, read here...

I prepared you an activity about this, I hope you like it.

Take care,



Hello! Here you can find the contents for our next exam. Good luck!

Preparing the exam


Conditional Sentences

Last days we have been studying the conditional sentences. I think that...

If we practice them, they will be easier to learn.
If we see some examples, we will understand them better.

If these examples were fun, we would enjoy more.
If we invented conditional sentences, it would be the best way to learn them.

So we are going to practice the first type of conditionals

And the second type.

And you know


Numbers and powers of 10

"Powers of 10" is a very useful way of writing down large or small numbers. Instead of having lots of zeros, you show how many powers of 10 you need to make that many zeros. See more here.
Can you imagine what size are the things around us? Have a look to the following site called "Scale of universe enhanced" and write a brief summary with your partner of three things on the web.

Let me know what you think in the comments,

Multiplying and dividing fractions

To multiply fractions, there are three steps:
1. Multiply the top numbers (the numerators).
2. Multiply the bottom numbers (the denominators).
3. Simplify the fraction if needed.
 See more about multiplication

Practice multiplying fractions

To divide fractions, follow these rules:
1. Turn the second fraction (the one you want to divide by) upside-down (this is now a reciprocal).
2. Multiply the first fraction by that reciprocal
3. Simplify the fraction (if needed)

See more about division
Practice dividing fractions by fractions.

Play the contest you always do by clicking here.

Take care,



Dancing has always been a popular form of entertainment, social interaction, and just plain fun!. Although the enjoyment of this activity has not diminished, today's dances differ greatly in style from dances of the Baroque period.

Search the Internet for pictures and video clips that illustrate some of the Baroque dances you have studied. Use the key words "Baroque dances".

You will be asked to give short presentations on your findings in our forthcoming classes.

Have fun


Adding and subtracting fractions

There are 3 simple steps to add/subtract fractions:
  • Step 1: Make sure the bottom numbers (the denominators) are the same
  • Step 2: Add/subtract the top numbers (the numerators). Put the answer over the denominator.
  • Step 3: Simplify the fraction (if needed).
See more here.
Practice adding and subtracting fractions with thesame denominator.
Practice adding and subtracting fractions withdifferent denominator.

If you feel comfortableEnlace with the operations, then try the game.

After that, play the contest.

Good luck!


More poetry ...

And what to say about our poets of the third year! Would you like to celebrate the World Poetry Day writing an acrostic with your name?

An acrostic poem takes a word, sentence, or phrase and makes the first letter of each the first line of a poem, for example …

Merry to share this year with you
Alive as you are, plenty of energy.
Grateful for watching you day after day
Determined to get the greatest success
Able, I’m sure to get everything

World poetry day

World Poetry Day is on 21 March, and was declared by UNESCO in 1999. The purpose of the day is to promote the reading, writing, publishing and teaching of poetry throughout the world.

To celebrate it we could turn some riddles into poems. Could you finish these ones? And why don’t you write your own poem?

This is a word which rhymes with cat,
It goes on your head because it's a ____.

I'm useful for journeys when you're going far,
I need lots of petrol because I'm a ____.

You'll find us near ponds or sitting on logs,
We jump and we croak because we are _____.

This is a word which rhymes with up.
You can drink out of me bcause I'm a ____.

This is a word which rhymes with bake,
I'm nice to eat because I'm a ______.

This is a word which rhymes with spoon,
I shine at night because I'm the______.

A neverending circle, a bright shiny thing,
It's on my fourth finger because it's a _____.


Equivalent fractions

What is an equivalent fraction?

If we look up the word equivalent in the dictionary, we would find something along the lines of, 'equal in value, force or measure'.So, as this word suggests, an equivalent fraction is a fraction that has the same value as another fraction, only the numbers are different.

See more information here

ACTIVITY: Finding equivalent fractions
  Find 5 equivalent fractions for 12. Does this picture help you? (Write your answer in the comments)

How do we do this mathematically?
By multiplying the top and bottom part of the fractions by the same number: 2, 3...

Practice more.

Take care,

PI day

Hi there,

Today we celebrate Pi Day as it is March 14 (or 3/14 in month/day date format), since 3, 1 and 4 are the three most significant digits of π in the decimal form.

Have a look at the Pi Day challenge and Pi Day activity.

Take care,



I have a present for you... Did you know that I love art, and specially Romanesque art? These are the images that you could find in the exam to comment on them tomorrow. So, don´t worry about any unknown o strange images.

Have a look

Bye and don´t be nervous! Only one thing: the exam is very, very long, as usual; sorry but I love this period!



Fractions from a gender point of view

Hi boys and girls,

Today we celebrate the International Women's Day, originally called International Working Women's Day. It is a day to remark women's economic, political and social achievements.

I would like to speak with you today about some data I found about the situation of women around the world, and others specific from Spain. Here you have some interesting fractions:

.1.  Women and girls do 2/3 of global labour.
2.  For every $ 100 earned by a man for his work, the woman doing the same received only 80. In an average working life, women earn half a million dollars less than men.
3.  In Spain, 6 out of 10 university students are women, although only 11 of 77 chancellors in our country are.
4.  In Spain, 38 in 100 women have stopped working for over a year for the birth of their children, while only 7 out of 100 men do so.
5.  19 out of 20 maternity requests for childcare leave are applied for by the mothers.
6.  In Spain, there are only 132 female deputies, of the 350 representatives in Parliament.
7.  In RAE (Spanish Academy of Language), there have only been 5 women out of 460 members in History.
8.  Only 10 out of the 100 honorary doctors in Spain are women.
9.  2 out of 3 of the world's illiterates are women.
10.Only 10 of the 100 Presidents and Boards of Directors of the IBEX-35 are women.
11.In the total of the governments of the EU, women represent only ¼.
12.Only 28 of every 100 workers in medium-high technology corporations are women.
 What can we do? What do you think about this?
 Let me know in your comments,



International Women's Day

Why is this day celebrated all over the world?
Why do we celebrate it on 8th of March?
Do we need such a day in the 21st century?
We will find the answers to these questions and more information in the links below.

What do they do?.

Carmen will help us to learn who has helped to change our daily life.

What do you know about the history of this day? Why is it necessary nowadays?

Do you know that by investing in women and girls, we can accelerate social, economic and political progress? Discover how.