Tetromino

Observe the below figures,  

In Figure 1, One $4\times 4$ square is filled by a tetromino shape . 
In the same way try to fill the other $4\times 4$ square grids (Fig.2 to Fig.5) using the other four tetrominoes ( and ). 

 Find which tetromino shape cannot fill the $4\times 4$ square grid completely.

     Fig 1                        Fig 2                  Fig 3                     Flg 4                       Fig 5

Count the number of dots in domino and multiply them.

Count the number of dots in domino and add them.

Count the number of dots in domino and subtract them.

Count the number of dots in each domino and divide them.

Count the number of dots in each domino and multiply them.

Number of tetromino are _____.

A tetromino is a shape obtained by combining how many squares together?