Showing posts from May, 2008 new design

My main math site,, has gotten a face-lift... with better NAVIGATION on the left sidebar. Hopefully you'll be able to find your way around better along all the articles, reviews, worksheets, and stuff there.

I especially want to draw attention to the ONLINE RESOURCES section. I used to have this on 9 pages... now I split it into 29 different pages, according to topic.

These pages feature the best online games, quizzes, tutorials, or websites on various math-related topics. Have your pick:

Online math resources menu

Addition and subtraction
Place value
Math facts practice
The four operations
Factoring and number theory
Statistics, Graphs, and Probability
Logic and proof
Problem solving & math projects
For gifted children
Math history
Math games and fun websites
Sites with interactive math tutorials
Math help & online tutoring
Review and test prep
Online math…

I will derive!

Just a fun little song (parody of "I will survive") for all of us who've taken calculus.

Heart of the Matter conference

Heart of the Matter will he hosting an online homeschool conference during July 30 till August 3.

What is a virtual conference all about?

"Each speaker will just log in at her/his scheduled time, with a plugged in microphone, speak about their topic (approximately 30-40 minutes), and then hold a Q/A session with the listeners (approximately 20-30 minutes). All the while the attendees will get to chat amongst themselves in true Instant Message format.

We really want the conference to be less like a "seminar" and more like a bunch of close friends in a chat room. We want everyone to feel comfortable. Some sessions will also be pre-recorded. Just wait till you see what some of your favorite home school personalities have done to educate and entertain you! At the end you will join in to chat with them, ask questions, and they will answer."

Well, yours truly is planning to be a speaker as well...
Anyway, here's a link for more info and you can sign up as well. Place my…

Marbles problem to solve

Here's a nice "brain teaser" problem sent to my way... probably a student who wants to know the solution. I'll post it for you all and the solution in a few days.

204 marbles are divided into 3 groups according to colour. Ahmad found that there are twice as many blue marbles as white marbles and there are fewer red marbles than blue marbles. Ben found that the number of marbles in each group are divisible by 4 and 6. Cally found that the number of marbles in each group is less than 100.

How many red marbles are there?

(I do not have a clue where the problem originates, but I DO LIKE it!)


Now, we need to find three numbers.

The one hint tells us that one number is double the other, and the third is less than the first (the doubled one). This won't yet get us started.

It is actually the latter hints that provide a starting point.

We learn the numbers are divisible by 4. They're also divisible by 6, which means they're divisible by 2 and 3. But we already …

Get Math Mammoth Clock for free - CurrClick promotion

UPDATE: The promotion is extended till the 15th of this month so that all can enjoy it (they've had some problems with so much traffic).

I'm sure most of you already know about this... CurrClick is having a mother's day promotion where they have 20 homeschool titles for a free download... and one of them is my Math Mammoth Clock book.

Just click here to download some of them -- or all of them! (You'll have to register if you haven't already.)

My opinion on Saxon math

People sometimes ask me of my opinion of Saxon math.

In a nutshell, I realize that Saxon math works for some children. However, it is not the way I would teach math.

Saxon math presents a concept in a lesson, then has a few exercises about it, and the rest of the lesson is review of previous concepts.

The NEXT lesson usually is not on the same topic as the previous lesson. It jumps around in topics tremendously. One lesson on geometry, next on fractions, next on addition, next on large numbers. It's unbelievably disjointed. It's not the concept presentation nor the exercises in Saxon math -- it is the way the lessons jump around that I dislike.

How can kids get a coherent view of mathematics studying that way?

Read how professor Hung-Hsi Wu has worded it (emphases and the additional note are mine):

"But I think that what perhaps disturbs me the most about Saxon is to read through it, I myself do not get the feeling that I am reading something that when that the children us…

Teacher appreciation week

I should have posted this earlier but forgot. I even missed one day!

Learning A-Z is having an open house this week; you can access their family of websites for free, one site per day.

The writing site is for today. Vocabulary site is coming up soon, and so is their science site. Lots to explore and download.

Gas price math

Today I just stumbled upon two sources discussing the price of gas in a comparative sense; one was a line graph comparing it to the past, the other was a world-wide comparison.

Both were interesting; and a resourceful teacher can now make all kinds of problems based on the data. First based on the list of gas prices in various countries, for example these come to mind. (And I'm just giving you ideas for a lesson on gasoline lesson; I'm not providing answers but if some of you want to, feel free to comment.)

Approximately how many-fold is the price of gas in Bosnia-Herzegovina as it is in the USA? In Egypt? In Venezuela?

If your mileage is 25 miles per gallon, find the price of driving a 120-mile trip in Germany and in the USA.

Looking at the inflation adjusted gas price in 2008 dollars now. Just reading the graph:

When was the price of gas at its lowest? At its highest? How much was it?

Find the price of gas (approximately) in 1930, 1960, and 1990 by reading the graph.

If you overl…

A simple triangle problem

Someone sent in this very simple question (a student?).
Leg b of the right triangle is twice as long as the base a.
If the area is 36 cm squared, what is the length in of the leg b?
A little bit of algebra helps in this problem.

FIRST strive to make a picture. Need a right triangle, the leg twice as long as the base. Here in my picture things aren't exactly to the scale, but it suffices for illustration purposes:

So we actually know that b = 2a.

The area of a triangle here is base times height over 2, and remember the height is the other leg, and it's twice the base:

area = ba/2 = (2a)(a)/2 , and this is 36 (given).

So we get our equation:

(2a)(a)/2 = 36

a2 = 36

a = 6.

The leg b is therefore 12 cm long. check: Legs are 12 and 6, so the area is 12 * 6 / 2 = 36.