The square root of number 121 is "11". What is the square root of the number "12345678987654321."?

Can you solve this picture maths equation?

The person who makes it has no need for it; the person who buys it has no use for it. The person who uses it can neither see nor feel it. What is it?

Forwards I am heavy, backward I am not. What am I?

Which three-digit number, made of consecutive digits, like 567, is 2 less than a cube and 2 more than a square?

A sundial has the fewest moving parts of any timepiece. Which has the most?

I come in different shapes and sizes.
Parts of me are curved, other parts are straight.
You can put me anywhere you like,
but there is only one right place for me.
What am I?

Move three sticks of the spiral below to form a square.

'Ferrari driver' easily beats the 'force driver' in a two-car race. How did Indian newspapers truthfully report so to look as a 'force drive' had outdone the 'Ferrari driver'? Think!!!

What does this mathematical rebus means ?