The sum of the first $n$ odd numbers is equal to .

Evaluate $69\times 71$.

Find the square of the following number using the shortcut methods.

$106$

Evaluate $88\times 92$.

Find the greatest number of five digits which is a perfect square. Also find the square root of the number so obtained.

Identify by mere observation, the numbers that are not perfect squares.

(i) $5184$(ii) $12,321$(iii) $16,928$(iv) $35,623$

Using the formula $(a-b{)}^2=(a^2-2ab+b^2)$, evaluate ${196}^2$.

Find the square of the following number using the shortcut methods.

$85$

Using the formula $(a+b{)}^2=(a^2+2ab+b^2)$, evaluate ${310}^2$.

Find the value of the following, using the column method: $(52{)}^2$

The difference of two perfect squares is a perfect square.

Find the value of the following, using the column method: $(96{)}^2$

Find the value of the following, using the column method: ${23}^2$