When I get multiplied by any number, the sum of the figures in the product is always me. What am I?

What is more useful when it is broken?

I am looking for a word that change both gender and number when i add the letter 'S'.

What Word am I Looking For ?

A man and a dog were going down the street. The man rode, yet walked. What was the dog’s name?

I know a nine-letter word having only one vowel.
Do you ?

These types of puzzles are known as charades. What you have to do is find two words that are referred to in the first stanza and the second stanza and put them together to form the third word in the third stanza.

Just for example, if my first refers to 'off' and my second refers to 'ice', then my whole will be office.

My first is present - future's past -
A time in which your lot is cast.

My second is my first of space
Defining people's present place.

My whole describes a lack of site -
A place without length, breadth, or height.

When I go in I might cause pain. I cause you to spit and ask you not to swallow. I can fill your hole. What am I?

The more of this there is, the less you see. What is it?

There are four 3-link chains. All you have to do is join them into a big 12-link chain. For joining two closed links, one of the links must be cut and placed onto the other link for closing.

How many minimum links will you have to cut to make the big chain?

I have four wings but can't fly.
I express no emotions.
I am found on the exact spot every time you look.
I keep toiling away with a little sound.

Do you know what am I?