Solution:

1

Explanation.
At every step number of joints goes down by 1.
i.e
8 have 6 joints
9 have 5 joints
5 have 4 joints
3 have 3 joints
7 have 2 joints
1 has 1 joint

You can also watch the video for an explanation

Solution:

LOTTO

Explanation:
Just flip the two rows 1 and 2 vertically, you will find the word "Lotto".

Solution:

Solution is shown in image below

Solution:

The matchsticks that are marked with red are to be removed and the final figure will have just two squares. You can remove either pair from the possible four ways.

Solution:

It can be done as shown in the picture below.

Solution:

As shown in the picture below, add matchstick to make 1st + symbol as 4.

Solution:

It can be done as shown below.

Solution:

It can be done as shown in the picture below.

Solution:

It can be done as shown below.

Solution:

Remove the same 2 matchsticks from each figure and move figure towards left 45 degrees, It forms the letters V W X Y.