What will be the units digit of the square of the following number?

$7286$

What will be the units digit of the square of the following number?

$8742$

Which of the following numbers are perfect squares?

$121$

Check whether the number is perfect squares?

$136$

Check whether the number is perfect squares?

$256$

Check whether the number is perfect square?

$321$

Check whether the number is perfect square?

The number is not perfect square. Give reasons?

$257$

The number is not a perfect square. Give reasons?

$4592$