A seven-year-old kid challenged his classmates that he can make the number one disappear by adding something to it.

How can he do that?

What is the word or phrase?

Find a 9-digit number, which you will gradually round off starting with units, then tenth, hundred etc., until you get to the last numeral, which you do not round off. The rounding alternates (up, down, up ...). After rounding off 8 times, the final number is 500000000. The original number is commensurable by 6 and 7, all the numbers from 1 to 9 are used, and after rounding four times the sum of the not rounded numerals equals 24.

Divide 110 into two parts so that one will be 150 per cent of the other. What are the 2 numbers?

You order chicken wings at KFC in the boxes of 6, 9 and 20. What is the largest number of wings that you cannot obtain by buying in any combination of the boxes?

The product of three consecutive numbers is 7980.
Then the sum of these consecutive numbers would be?

By removing one matchstick and adding one matchstick, can you convert the word "ZOO" to an animal name?

Can you count the number of quadrilaterals in the picture below?

Can you solve the tricky chess rebus puzzle below by ciphering the hidden meaning?

In a mathematical quiz, you are asked the following question:

Use three 9s in a mathematical expression without dividing or multiplying to form the number one.

Can you answer the question?