10-May-2010, 12:05 AM

Many of them especially in India do not understand the basic principles of mathematics or science while they are learning. They tend to mug the things up just like they mug the Shlokas believing it to be true without questioning "how". This will hinder the scientific thinking in child and the child will tend to believe in superstitions blindly. Scientific and mathematical theories can always be proved experimentally.

The best and simple example is negative number multiplied by a negative number. Teachers should demonstrate this in the class just like a lab experiment.

Consider multiplication of two integers a and b, i.e a x b.

Consider the number line with negative side as west and positive side as east and you standing at 0.

West <--- ___-3___-2___-1___|y0u_r_here|___+1___+2___+3___---> East

If a is positive then face yourself towards east,

If a is negative then face yourself towards west.

If b is positive, then move forward,

If b is negative, then move backward.

Now consider a x b and your initial position at 0,

you will face towards east (a is positive), move forwards (b is positive). You will end up on positive side.

Now consider -a x b and your initial position at 0,

you will face towards west (a is negative), move forwards (b is positive). You will end up on negative side.

Now consider a x -b and your initial position at 0,

you will face towards east (a is positive), move backwards (b is negative). You will end up on negative side.

Now consider -a x -b and your initial position at 0,

you will face towards west (a is negative), move backwards (b is negative). You will end up on positive side.

Thus minus times minus is a plus!

'a' tells you how big must be the steps while you move, 'b' tells how many steps you have to take, while the minus or plus sign tells you the direction.

Example:

-2 x -3 ,

This says face yourself west (-a) and move backwards (-b) by taking 3 steps of 2 feet each. You will end up at +6 feet towards east from 0.

The best and simple example is negative number multiplied by a negative number. Teachers should demonstrate this in the class just like a lab experiment.

Consider multiplication of two integers a and b, i.e a x b.

Consider the number line with negative side as west and positive side as east and you standing at 0.

West <--- ___-3___-2___-1___|y0u_r_here|___+1___+2___+3___---> East

If a is positive then face yourself towards east,

If a is negative then face yourself towards west.

If b is positive, then move forward,

If b is negative, then move backward.

Now consider a x b and your initial position at 0,

you will face towards east (a is positive), move forwards (b is positive). You will end up on positive side.

Now consider -a x b and your initial position at 0,

you will face towards west (a is negative), move forwards (b is positive). You will end up on negative side.

Now consider a x -b and your initial position at 0,

you will face towards east (a is positive), move backwards (b is negative). You will end up on negative side.

Now consider -a x -b and your initial position at 0,

you will face towards west (a is negative), move backwards (b is negative). You will end up on positive side.

Thus minus times minus is a plus!

'a' tells you how big must be the steps while you move, 'b' tells how many steps you have to take, while the minus or plus sign tells you the direction.

Example:

-2 x -3 ,

This says face yourself west (-a) and move backwards (-b) by taking 3 steps of 2 feet each. You will end up at +6 feet towards east from 0.