Friday, January 11, 2013

Sunday, February 21, 2010

Centre of Cravity

I am planning to make a balancing toy with a Grade One class tomorrow

Thursday, October 22, 2009

Math Patterns

I've been in a debate these last few days over multiplication tables. How do you teach them. I've heard from a number of people who say that they need to be memorized. My problem with this is that only a handful of students seem capable of doing this and with less time being spent studying at home this numbeer is getting smaller.

Students who are not successful in memorization are lost when memory fails. The student who forgets 4 x 6 makes no effort to solve this problem. He has failed.

I think that students need to be taught to recognize patterns. Then, when memory fails the real math begins.

"I don't know 4 x6 but 2 x 6 is 12 so if I double 12.."

" I don't know 4 x 6 but I know you can halve and double so 4 x6 is the same as 2 x 12 or 3 x 8 ."

Pentz Patterns in Math Name ______________________

2 x 3 = _______ 4 X 3 = ______

2 x 4 = _______ 4 x 4 = ______

2 x 9 = ______ 4 x 9 = ______

2 x 5 = ______ 4 x 5 = ______

2 x 8 = ______ 4 x 8 = ______

2 x 6 = ______ 4 x 6 = ______

2 x 7 = ______ 4 x 7 = ______

2 x 2 = ______ 4 x 2 = ______

2 x 1 = ______ 4 x 1 = ______

2 x 0 = ______ 4 x 0 = ______

Wednesday, September 16, 2009

Number Patterns

I'm subbing 2 days for a grade5/6 class next week. The class is doing number patterns in math and I was looking for something fun to do with fibonacci numbers. Most online activities say the numbers are 1 1 2 3 5 8 13 21 etc. and they are very common in nature. Go out and find them. I spend a lot of time outdoors and I know a lot of plants like clover have 3 leaves and many flowers have 5 petals but there are a lot of plants out there that don't seem to fit.I think it may be interesting to us some cube links or other blocks to build a pattern. We can use calculators to divide. 5/8 = 0.625 8/13 = etc. Has anybody done anything with these numbers ?

Web Sites
Cyclic Number (gr.5,6)
Calendar Math (gr.2 -6)
Function Machine
Fibonacci Numbers and Nature
Fibonacci in Nature (pictures)
Math is Fun Fibonacci
Number Cracker
Pine Tree number Patterns
Interactive Hundred Square
Shape Pattern Prediction Version 1

Thursday, May 7, 2009

Elephant's Toothpaste

Place a tablespoon of yeast in 3 tablespoons of warm water. Allow time for the yeast to dissolve.
Place 2 cups of hydrogen peroxide (03%) in an empty 2 litre pop bottle. Add two squirts of liquid soap. Pour in the yeast.

Wednesday, April 29, 2009

Cartesian Diver

Fill 6 or more 2 litre plastic bottles with water. Have students form groups of 2 or 3.
Students need to use large container filled with water to float glass medicine dropper.
Have them adjust amount of water so that dropper just floats. In dropper shown 1 ml. of water works well.
Place the dropper in the bottle , tightly close lid and squeese the bottle with two hands. The pressure contracts the water in the dropper allowing more water to enter the dropper.

Friday, April 24, 2009


I have a number of science demos that I like to do with elementary students. Some require a little practice or prep time but you soon become confident with them.
I have never had a problem with this demo and have done it dozens of times but I still expect the glasses to go crashing to the floor.
We begin with a discussion of Sir Isaac Newton. There always seems to be one or two students who claim to have heard of him . I have been scared to ask how or where. I talk a little about gravity and the Law of Inertia.
An object at rest tends to stay at rest and an object in motion tends to stay in motion with the same speed and in the same direction unless acted upon by an unbalanced force.
I mention pulling someone on a sled and how you have to use more energy to get the sleigh moving although sleds and toboggans are probably as rare today as hearing about 17th century physicists .
Then we count to 3 and I smash the stick.
Here are a few tips:
1. Originally, I saw this done with pins at the ends of the stick. I don't use them anymore and don't have to worry about losing them. ( I always thought the pins were cheating a bit.)
2. Do not let your significant other catch you using or even looking at the best crystal.
You can pick up some nice wine glasses at most dollar stores. Make sure you use wine glasses because regular drinking glasses don't have the same effect.