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.

A word I know has six letters it contains, remove one letter and 12 remain. What is it?

This puzzle is for Harry Potter fans. Do you know why Tom Riddle is called Lord Voldemort?

I add 5 to 9 and get 2. The answer is correct, so what am I?

John bought 150 chocolates but he misplaced some of them. His Father asked him how many chocolates were misplaced.
He gave the following answer to him:
If you count in pairs, one remains
If you count in threes, two remain
If you count in fours, three remain
If you count in fives, four remain
If you count in sixes, five remain
If you count in sevens, no chocolate remains.

Can you analyze the statements and tell us how many chocolates were lost?

A tree doubled in height each year until it reached its maximum height over the course of ten years. How many years did it take for the tree to reach half its maximum height?

Move three sticks of the spiral below to form a square.

I have a five and a three-gallon jar. Assuming there is an infinite supply of water, how can I measure one-gallon water?

If you read clockwise, you can form a word by inserting three missing letters in the picture given below. Can you do it?

What is so fragile that saying its name breaks it?