Spiders and beetles

I sent you on friday a question about the word-problem we made in class last week. This was my mail:

If you remember the word-problem about spiders and beetles there were only 30 'bugs' in total.  All of them had 152 legs in total (8 per a spider and 6 per a beetle), but we have discovered that this is impossible. According to that I have two questions for you: If there are only 30 individuals...

                 

How many legs at a minimum do we need to make the word-problem correct? How many legs at a maximum? 
I promise a positive mark to those who get the right answer, but this offer will last only for this weekend.

Juan Antonio, Jesús and Rafa got the positive marks, congratulations! Here is the most complete answer from Juan Antonio:

The first answer is: 29x6+8=182 6(30-x)+8x=182 180-6x+8x=182 -6x+8x=-180+182 2x=2 x=1  There is 1 spider and 29 beetles.

The second answer is: 29x8+6=238 6(30-x)+8x=238 180-6x+8x=238 -6x+8x=-180+238 2x=58 x=29 There are 29 spiders and 1 beetle

Congratulations!!

"I'm thinking of a number..."

Ok you guys, let's see if you can do it. The challenge is this (use comments for this exercise):

1. We are going to start with seven times three from the class list. That person has to make one "I'm thinking of a number" card.
2. In decreasing order, the next one will solve the number.
3. The one who wrote the card will say if it's correct or not. If not, he/she will say the answer.



I'm thinking of a number

4. The one who tried to find the number will write another "I'm thinking of a number" card and so on.

I will arbitrate the whole thing, so get focused on the blog and on my comments. Click on the image to find the examples we made the other day.

We can start now until next friday (april 1st).

Decimals, Fractions and Percentages

You already know that you can say the same thing in English, Spanish or French. For example:

• Hola amigo
• Hello friend
• Bonjour ami

The same thing happens with numbers. You can write them as a fraction, as a decimal or as a percentage. Imagine that you have no calculator at all and you have to calculate 16% of 120.

1. Write how can you make this calculation and 
2. tell me the decimal number and the simplest fraction expressed by this percentage.

END DATE: Next Friday, February 25th.

Divisibility Bingo!

Congratulations to

Inma and Guillermo 

for their positive mark playing bingo!! This one was trickier, so you must work harder if you want a positive point.

Best luck for the next bingo!!

Erathostenes test

In this post you will see a presentation about Erathostenes, and then you will have to answer a test. Who was he? Why was he so important? Open your mind and...

let's see what you can learn about Erathostenes

(Time limit: December 1, 2010)

Powers and Radicals BINGO!!

Congratulations to

Martín, Juanma, Rafa and Coke 

for their positive mark playing bingo!! All of you made an exellent work and tried really hard to get the positive, but I only had four to give out.

Best luck for the next bingo!!

A hard addition

Discover the value for each symbol

to make a perfect addition.

	&	#	#
	#	5	&
+	1	&	#
	*	1	*

Use the comments to answer.


Translated and adapted from the book "El País de las mates 1" by Miquel Capó