Sidewalk Chalk Number Line

A number line is a basic way to represent where numbers go and describe the order of numbers.  It is a great way to help develop number sense and can be used to demonstrate concepts such as negative numbers, addition, subtraction, fractions, decimals, and more.  A basic number line can be drawn by making a straight line then drawing hash marks at evenly spaced intervals along the line.  Often, zero is in the middle and negative numbers count from zero to the left while positive numbers count from zero to the right.  This does not always need to be the case depending on the type of numbers you are going to use and what you are trying to show.

To help a child understand the number line use sidewalk chalk and draw a number line.  Have the child pick a number and stand on it then give them instructions and have them move along the number line based on that instruction.  You can say things like "add 3" or "take away 7".  Help your child move appropriately on the number line so they can see that if they were standing on 4 and they subtracted 7 they would then be standing on -3.

Some variations to this to make it more challenging would be to use fractions or decimals and have the number line range from -1 to 1.  Either you or your child can fill in the number line and put the fractions or decimals where they belong.  This might be trickier for you to give them instruction and have them land on a hash line but you can have the estimate their location or you can work out equations first so you know it works every time.

You can also ask your student to add negative numbers or subtract negative numbers.  This can be challenging at times but it really helps if you have your student face the way the sign is telling them to go and they move forward if they add or backwards if they subtract.  For example, if a student is standing on 1 and they are asked to take away -3, they would face the negative direction and step backwards so their overall movement would be in a positive direction.

Science Fair & Project Night

I want to thank all of my students for your hard work!  I really think it paid off with an amazing display of posters, experiements, creations, and research.  I'm sorry I was not able to make it back to school for the project fair but I did go around to all of the teachers in the building bragging about the incredible job my kids did and how rad the hallways looked!!!

I hope you all had a great time working on your projects and I can't wait to see your presentations on Tuesday!

Science Fair Project

We are going to have a science fair in our class.  These are some of the guidelines for how we plan on completing the science fair projects.  First, we are going to write proposals.  These proposals are going to outline the project each student would like to do for the science fair.  Their projects can be an experiment, exploration or invention.  It should be something they enjoy and would like to learn more about.  Projects will be individual assignments (unless a student can make a really good argument for needing two people). Supplies are limited so students will need to include the supplies they need in their proposal and how the plan on obtaining these supplies.  If a student is not sure how supplies can gathered then we can discuss options for finding the supplies.  These proposals will be due January 13th.

After student proposals are approved, we will begin working on our science fair projects.  The time we spend will be following the scientific process by researching, writing hypotheses, gathering data, constructing, writing conclusions, and any other pertinent step.  At the end, students will present their science fair project to the class.  This should take place January 27th (subject to change depending on the schedule for the following week).

Types of Energy

Potential Energy: A type of energy that is stored.  It is not actively being used but it can be converted to Kinetic energy when its being used.

• A car that is not moving but has a full tank of gas, a bouncy ball sitting on a table, food that has not been eaten

Kinetic Energy: A type of energy that will act upon an object to create work.  There are several types of energy that are all classified as kinetic energy.

• Light Energy
• Light, Sunshine
• Sound Energy
• Sound waves
• Chemical Energy
• Food as our body digests it, a battery
• Mechanical Energy
• Our bodies move while using Mechanical energy, any motion
• Heat Energy (sometimes this is listed separate from Kinetic energy but not everyone agrees with that)
• Toaster as it browns bread, light bulbs (some more than others)

Work & Power

We have been studying work and power.  Work is what happens when energy acts on an object.  For example, a toaster uses electrical energy and converts it to heat energy.  The work done by a toaster is toasting bread.  It is a change in an object due to energy.  The way work is calculated when an object is moving up is by multiplying the mass of an object by the rate of gravity (9.8 meters per second squared) by the height the object is being lifted.  We have used the example of climbing the stairs at Trillium.  The height of the stairs is 4 meters and if a student has a mass of 60 kg, the work could be calculated by
W = 60 x 9.8 x 4.  The unit for energy and work is Joules.

Power is the rate at which work is done.  It can be calculated by dividing Work by time (P=W/t).  This concept is one that is very similar to our concept of power used by most students in every day language.  The more powerful a student was going up the stairs it meant they either moved more mass at the same time or moved the same mass at a faster time.  Power's units are watts.

Energy

We are going to start exploring ENGERY.  Energy is the ability to do work or to make change.  If you think about your body, in order to make your body move, you need energy.  It's not something you can tell when energy is present.  Seeing a light on, feeling the wind blow, feeling heat from a fire and hearing noises are all ways of experiencing energy.

There are two types of energy.  The first is POTENTIAL ENERGY which is a stored energy.  A car that is off but has a full gas tank, snow at the top of a hill, and food all have potential energy.  KINETIC ENERGY is the other type of energy and its the energy possessed by a moving object such as a snowball being thrown, my body while typing this blog post, and a moving car.

A lot of things will have both potential and kinetic energy such as a bouncy ball.  As the ball drops, it has more and more kinetic energy because its velocity (or speed) is increasing as it goes to the floor.  After it hits the floor and bounces back up, the kinetic energy transforms into a potential energy.  The amount of energy in the bouncy ball never changes (unless something else causes it to change like the impact of the ball with the floor) but it can continue to change back and forth between potential and kinetic energy.

Newton's Laws of Motion

Newton's First Law of Motion:
This law talks about INERTIA.  It means that an object that is at rest wants to stay at rest unless a force acts upon the object.  This means that an object will continue to stay still unless something makes it move.  Also, an object in motion wants to stay in motion unless a force changes its motion.  That means that if an object is moving there must be a force such as friction or air resistance to cause that object to stop.  An object already moving must also have a force act upon it in order to change its direction.  If something is traveling straight, it must hit a wall, another object, a bump in the road, or encounter another change in force to make it change its course of motion.

Newton's Second Law of Motion:
This is the law that tells us that F=m*a or Force = Mass times Acceleration.  This means that the force an object has can change depending on the mass of the object and the acceleration of the object.  We experienced this the day we did the three different labs.  One team rolled a car down a ramp into the back of another car and found that the faster the car traveled the further the second car moved.  Another team swung a pendulum into a cardboard object.  When the mass of the pendulum was increased, the distance the cardboard was pushed increased.  The third team used the force plate to determine the amount of force a ball had when dropped from different heights.  The higher the ball started, the more acceleration it had when it hit the force plate and therefore it had more force.

Newton's Third Law of Motion:
This law is the law that says every action has an equal and opposite reaction.  We've talked about this with the Normal Force.  Remember the example of a book sitting on a table?  The normal force is a force that the table pushes onto the book and it is equal and opposite of the force of gravity.  The other example we discussed in class is an astronaut firing a gun in outer space.  The astronaut would fly backwards with the same amount of force as the bullet being propelled from the gun because when a gun is fired, the bullet and the person experience a force that is equal and opposite.  Force diagrams are great ways to show these forces because the vectors indicate the direction of the force and the length of the vector arrow tells us how strong the force is.  When the arrows face opposite directions and are the same length, that shows us on the force diagram that the forces are equal and opposite.