What have one eye but still cannot see?

What does the below mathematical rebus mean?

This is a classy optical illusion puzzle. What more you can find except bricks in the image below?

A number with an interesting property:

When I divide it by 2, the remainder is 1.
When I divide it by 3, the remainder is 2.
When I divide it by 4, the remainder is 3.
When I divide it by 5, the remainder is 4.
When I divide it by 6, the remainder is 5.
When I divide it by 7, the remainder is 6.
When I divide it by 8, the remainder is 7.
When I divide it by 9, the remainder is 8.
When I divide it by 10, the remainder is 9.

It's not a small number, but it's not really big, either.
When I looked for a smaller number with this property I couldn't find one.

Can you find it?

What do you get if you add 2 to 100 four times?

John enters a small room. The Door Closes.
When the door opens, John is in a larger room.

Explain?

A man died, leaving $10,000,000 for his widow, 5 sons and 4 daughters. Each daughter received an equal amount, each son received twice as much as a daughter, and the widow received three times as much as a son.

How much did the widow receive?

Replace each alphabet with the number (1-9) to make the below equation correct.

AB * C = DE - F = GH / I

Make the seating arrangement of 10 children in such a way that there are 5 rows with 4 children in each row.

John can place six large boxes or nine small boxes into a carton.

Can you find out in how many cartons can he place sixty-six boxes in total?