## Arithmetic operations

*Why is minus into minus a plus?*

*Why is minus into plus a minus?*

For answers, read on…

## Number line

*What are Natural numbers, Whole numbers and Integers ?*

*Why do we need Negative numbers?*

*Why is -1 less than 0? How can there be something smaller than nothing?*

*Is there anything rational about Rational numbers?*

*What is behind the random sequence of unending decimal part in Irrational numbers?*

For answers, read on…

## Angles – The seed of Trigonometry

*Angle in degrees or radians? Which one to choose? *

Why do we express angles in terms of fractions or multiples of π i.e. 30°, 90°, 180°, 360°… as π/6, π/2, π, 2π … ?

*Why does a circle have 360°? Why is 360° = 2π?
*

*What is behind the periodicity of trigonometric functions?
*

For answers, read on…

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