## Simple Motor With the 4th Graders

To design a simple motor all we need is a number of batteries, neodymium magnets, metal screws or nails, and some copper wires (they do not get attracted by magnets, and they conduct electricity).

The 4th graders were super excited when Bala and I entered the class with a box on our hand. Then i explained that we would be doing a small experiment with magnets and some batteries. We split the class into four smaller groups and handed each group the required number of components. The explanation on how to connect the components was shown, and the children made their own motors. While doing the motor they realized that when the batteries polarity were reversed the direction of the spinning screw also reversed.

Once the children were done with the motor, they did a puzzle on water and weighing.

” If you had a 5-liter bowl and a 3-liter bowl, and an unlimited access to water, how would you measure exactly 4 litres. ”

all came up with interesting ideas and explanations.

## Nullator and Norator

Nullator

In electronics, a nullator is a theoretical linear, time-invariant one port defined as having zero current and voltage across its terminals. Nullators are strange in the sense that they simultaneously have properties of both a short (zero voltage) and an open current(zero current). They are neither current nor voltage sources, yet both at the same time.

Inserting a nullator in a circuit schematic imposes a mathematical constraint on how that circuit must behave, forcing the circuit itself to adopt whatever arrangements needed to meet the condition. For example, the inputs of an ideal operational amplifier(with negative feedback) behave like a nullator, as they draw no current and have no voltage across them, and these conditions are used to analyze the circuitry surrounding the operational amplifier.

A nullator is normally paired with a norator to form a nullor.

Two trivial cases are worth noting: A nullator in parallel with a norator is equivalent to a short (zero voltage any current) and a nullator in series with a norator is an open circuit (zero current, any voltage).

Norator

In electronics, a norator is a theoretical linear time invariant one port which can have an arbitrary current and voltage between its terminals. A norator represents a controlled voltage or current source with infinite gain.

Inserting a norator in a circuit schematic provides whatever current and voltage the outside circuit demands. For example, the output of an ideal opamp behaves as a norator, producing nonzero output voltage and current that meet circuit requirements despite a zero input.

A norator is often paired with a nullator to form a nullor.

Two trivial cases are worth noting: A nullator in parallel with a norator is equivalent to a short (zero voltage any current) and a nullator in series with a norator is an open circuit (zero current, any voltage).

Reference : Verhoeven C J M van Staveren A Monna G L E Kouwenhoven M H L & Yildiz E (2003)

## Learning Algebra With the the help of scratch

After finished Geometry i was switched to Algebra. Mastering algebra is important for moving on to nearly all other types of mathematics in  school. However, even the most basic algebra skills can be tricky for beginners to understand the first time they encounter them. I was in the need to know their prior knowledge in algebra in order to build on that (if that was conceptual) or correct them (if that was misconception). So, I gave some equations to solve, asked some stories (Multiplication & Division) and gave them small puzzles  to understand their understandings in algebra.

Except few, all posses some sort of difficulties. Some of them could not able to interpret the question, some of them having difficulties in calculation part, Some were guessed the answers. From that i inferred they need more explanation to understand the concepts. So, i took them to computer lab to practise algebra using scratch programming. First, i gave an expression of 5x+10 and asked them to draw bar graphs in scratch,                                     where x = 1,2,3,4,…….10(with guidance).

Then, i asked them to find out the value of x in the following equation 5x+10=70.

<iframe allowtransparency=”true” width=”485″ height=”402″ src=”http://scratch.mit.edu/projects/embed/53042546/?autostart=false”

What I was  inferred, they could learn(understand) the things comparatively quicker by programming than doing it manually (as procedural). Hence i decided to add one more concept on that just like fun by asking them to draw multi-stair case like structure by modifying the program   ( under guidance).

<iframe allowtransparency=”true” width=”485″ height=”402″ src=”http://scratch.mit.edu/projects/embed/53046628/?autostart=false”

## Mathematics Experiments with 7th Grade Students

The lack of a good education ( sometimes, misunderstanding  or partial understanding of concepts)  is one of the biggest issue across the globe.  Having an educational infrastructure (i.e. schools) is only half the battle. Teacher training is crucial and often the missing element. In order to get a good education children need to have teaching methods which motivate and offer them freedom to learn while in school, and this is where the “chalk and talk” teaching fails.

“Chalk & Talk” is a formal method of teaching with a blackboard and the teacher’s voice as its focal point. This method is used in classrooms across the world. However, this formal and somewhat unimaginative teaching method has come under scrutiny, with many people suggesting that teachers should not rely solely on this technique if they want to engage and inspire their students. Another criticism is that this method of teaching tends to go with the pace of the fastest learner and can leave a lot of children behind. That is, this “Chalk & Talk” method fails to stimulate all the students’ interests in learning. Education needs to be more practical, should allow children to express themselves and learn independently at their own.

So we decided to handle the mathematics class with some programming tool like GeoGebra  ( used to do Geometry) and Sratch ( Syntax free programming). At my first class with 7th graders, i started with GeoGebra. Because, most of the students follow only the procedure not the concepts behind the procedure.

During that period, they learnt about how to draw Equilateral Triangle & Isosceles triangle in GeoGebra (under some different kinds of condition) and their properties. (Here, i enclosed some pictures of my students’ work in Geometry).

This practice made the students to do their text book exercises by their own. Of course, I guess, it took me comparatively more time than “Chalk & Talk” method.

But It doesn’t matter when the students reproduced the things by their understanding.

## My First Interaction with Children

My First Proper Interaction with Children (6th graders)

We made a device called ‘SpeeDE’ that measures the speed of an object. We thought that taking this device to school and showing it to the children would be something new to them. One day I took the device to the sixth graders. Everyone saw SpeeDe in my hand and were very eager to know about it.
I started with telling them simple stories on speed and distance.
Eg, I travelled at a speed of 20km/hr, how much distance would i have covered for 3 hrs?

Then i asked the students to make up their own stories. Lots of new stories were made up.
But they had difficulties in the units(km/hr, m/s). They were not completely comfortable with the units.
After most of them had finished telling thier own speed and distance story, it was time to measure something from our device. I started with dropping a pencil case from about a metre to measure the speed of that and asked them to guess the speed. All types of random answers came up.
Then i dropped it from about half a metre and then dropped it from close to the device. The students who were pretty close to right answer were really happy and excited.
Then i asked why does the speed vary when I drop the pencil case from different heights. Some managed to tell that as the height increases the speed of the object also increased which was pleasing to hear.
Then at the end of the class we measured the speed of their punch and kick etc..
Everything was totally a new experience for me. I came to know that handling a class is not that easy as i expected.
Students tend to get more engaged in the class when we bring hands on stuff or else its not that easy to handle a class !!