Find the squares $105$ using the observation method:

Find the square of $98$ using the observation method:

Find the square of $308$ using the observation method:

Find the squares of $27$ using the diagonal method.

Find the squares of $44$using the diagonal method.

Find the square of $56$ using the diagonal method

Find the square of $32$ using the diagonal method:

Find the square of $64$ using the diagonal method:

Find the square of $91$ using the easy method.