Can you convert the number zero(0) into a positive number using just one mathematical operator ?

What can go through glass without breaking it?

What number does the below three word/phrase identify and why?
1. Deck
2. Year
3. Singing in the Rain

Begin with a word, five letters to my name,
Remove the first and last but I am the same
Take out my middle and still, I remain.
What word am I?

Can you divide the below-given shape into four equal and identical pieces?

I taste better than I can smell. Who am I?

I am eight letters long - "12345678"
My 1234 is an atmospheric condition.
My 34567 supports a plant.
My 4567 is too appropriate.
My 45 is a friendly thank-you.
My 678 is a man's name.

What word am I?

You need to move three matchsticks to form three squares. Can you do it?

What Does this text mean:

important=important

If "P" means "-", "Q" means "/", "R" means "+", and "S" means "*" then find the value of the following:

21 Q 7 R 9 S 10 P 13