After the December, 2015 issue, My School Rocks will no longer be in publication. I would like to express my deepest appreciation and gratitude to Ms. Jody Werner Greenwald who allowed me this wonderful opportunity to be a writer. You are truly an inspiration and if I can be half the writer that you are, I will have accomplished something great!

**http://www.myschoolrocks.com/stem**## December, 2015 - Final issue!

## September, 2015

## May/June, 2015

If pi truly is the greatest positive number, could it also be the greatest negative number too?

For a fun hands-on activity to show that pi is approximately 3.14, visit my class page:http://ppes4thgradems.weebly.com/hands-on-math.html.

*-*Caeden*, fifth-grade student at Ballantyne Elementary School**Many people have asked questions like this one for thousands of years. To answer your great question, let’s define what positive, negative, greatest and pi really mean.*

A positive number is any number that is larger than zero. A negative number is just the opposite: a number that is less than zero. The meaning of “greatest” is that nothing is higher or larger.

Now let’s look at pi. What is it? Simply stated, pi is the circumference of (or the distance around) a circle divided by its diameter (distance across). No matter how big or how small a circle is, when you divide its circumference by its diameter, you will always get approximately 3.14. It is a number whose decimal digits never end!

Because pi is approximately 3.14, it can’t be the greatest positive (nor the greatest negative) number. That honor goes to something that isn’t really a number but an idea: infinity (∞). Infinity goes on forever both above zero and below, as shown on the number line: ∞ ... -3, -2, -1, 0, 1, 2, ... ∞.A positive number is any number that is larger than zero. A negative number is just the opposite: a number that is less than zero. The meaning of “greatest” is that nothing is higher or larger.

Now let’s look at pi. What is it? Simply stated, pi is the circumference of (or the distance around) a circle divided by its diameter (distance across). No matter how big or how small a circle is, when you divide its circumference by its diameter, you will always get approximately 3.14. It is a number whose decimal digits never end!

Because pi is approximately 3.14, it can’t be the greatest positive (nor the greatest negative) number. That honor goes to something that isn’t really a number but an idea: infinity (∞). Infinity goes on forever both above zero and below, as shown on the number line: ∞ ... -3, -2, -1, 0, 1, 2, ... ∞.

For a fun hands-on activity to show that pi is approximately 3.14, visit my class page:http://ppes4thgradems.weebly.com/hands-on-math.html.

*Response by Don Miller, fourth-grade teacher at Palisades Elementary School*## March, 2015

**Why don't oil and water mix together?**

- Rheaa, second-grade student at Providence Spring Elementary

Imagine you are wearing thick winter clothing while your best friend is dressed for a hot summer’s day at the beach. Now pretend that you are both placed in a huge room where one side is really hot and one side is very cold. Because you are dressed for the cold, you will go to the cold side, while your friend will go to the hot side. You are both in the same room but in different places within that room.

In a way, that is the same as oil and water separating. It has to do with density. Density is the measure of how solid something is or, more simply, how much “stuff” is in something. Because you are dressed for the cold, you have more density than your friend does, so each of you will be more comfortable if you’re both in different temperatures!

All living and nonliving things are made up of molecules and tiny atoms. One difference is how tightly packed together the molecules are. Water molecules are more tightly packed together than oil, so water is heavier and oil is lighter. If you took a long ruler with a heavy rock at one end and a feather at the other and held it at the middle, the heavier side with the rock will try to tip over before the feather side. That is why when you mix oil and water, the oil will rise to the top.

To do a fun experiment making your own lava lamp using oil and water, go to my class page: http://ppes4thgradems.weebly.com/try-this-at-home.html

*Response by Don Miller, a fourth-grade teacher at Palisades Park Elementary*