January 31st

Today it´s about statistics.

Collecting data
Listen to this and solve the activity about tables and bar charts.
A first test.

GRAPHS AND DIAGRAMS
About pie charts: learn here what a pie chart is and how you draw one .

1. With Valentine´s Day just around the corner, this exercise just seemed appropiate: try and answer the questions.
2. And one with some vocabulary.

We can draw graphs using OpenOffice´s Calc:
After selecting the data on the spreadsheet, go to "Insert" and then "Chart". Select the kind of graph you´re interested in and the program would do the rest. You can modify the graph by addind a title, changing colors or the legend, etcetera.
3. Use the data on the page to draw a first pie chart
4. Use the data on the page to draw a second pie chart


About bar charts:
5. Complete the sentences on this one.
6. Use the data on exercise 3 to draw a bar chart using Calc.


About frequency polygons:
- An activity about frequency polygons (and more).
- And learn how to draw one (with grouped data):


And finally, a very, very easy test about graphs.

January 10th

Inequalities
As you already know, we use the following symbols:


Solving inequalities
"Solving'' an inequality means finding all of its solutions. A "solution'' of an inequality is a number which when substituted for the variable makes the inequality a true statement.
For example: 2 is a solution of 2x-3<5 because 2·2-3<5

When solving inequalities, there are certain manipulations of the inequality which do not change the solutions:

Rule 1. Adding/subtracting the same number on both sides.

Rule 2. Multiplying/dividing by the same POSITIVE number on both sides.

Rule 3. Multiplying/dividing by the same NEGATIVE number on both sides AND changing the orientation of the inequality sign.

ALWAYS EXPRESS SOLUTIONS AS AN INTERVAL(S)