My apologies

Pues eso, que mis excusas, espero volver a la carga con energía. Y con buen humor, que parece que la Jefatura de Estudios me tiene un poco borde últimamente... Os dejo una canción de mi época de instituto.

Repaso de potencias y raíces

Hola chic@s,

tras unas semanas complicadas, vuelvo a la carga con el blog. Os dejo unos ejercicios que he estado preparando para que podáis practicar más con potencias y raíces. Están en castellano.

Espero que os sean útiles, si necesitáis algo, ya sabéis donde estoy.

Saludos

ALICIA

Ejercicios

Ejercicios ya resueltos (para corregir, una vez intentados)

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.

ALICIA

0.7 TARGET

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,
ALICIA

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,
Cheers,
ALICIA

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,
ALICIA

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 the same denominator.

Practice adding and subtracting fractions with different denominator.

If you feel comfortable with the operations, then try the game. 
After that, play the contest.

 Good luck!

ALICIA