Rounding Off Numbers

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.




Similar Math Riddles

Pooja gave Neha as many Ponds as Neha started with.
Neha then gave Pooja back as much as Pooja had left.
Pooja then gave Neha as back as many Ponds as Neha had left, which left Pooja broke and gave Neha a total of 80 pounds. How much did Pooja and Neha have at the beginning of their exchange?

Asked by Neha on 04 Nov 2026


Christina, Allison and Lena are 3 daughters of John a well-known Mathematician, When I asked John the age of their daughters. He replied "The current age of her daughters is prime. Also, the difference between their ages is also prime."

How old are the daughters?

Asked by Neha on 05 Aug 2023

A cricket has 6 legs, a squirrel has 4 legs and a spider has 8 legs.

In a local zoo, it was found that the total number of legs is 612. Also, there are equal number of each of the above animals/insects.

Can you find out how many animals are there in the zoo?

Asked by Neha on 06 Feb 2021


Can you solve this tricky maths equation problem by replacing it? mark with the correct symbol?

19834 -----: 187
15921 -----: 153
17561 -----: 139
13734 -----: ???

Asked by Neha on 28 May 2023

Can you make the number 24 by utilizing the numbers 1, 3, 4 and 6? You must use one number only one time and you can use mathematical operation symbols anytime anywhere.

Asked by Neha on 18 Jan 2026

There is a straight highway. Four different villages lie on that highway. The distance between them is different. The third village is 60km away from the first village; the fourth is 40 km away from the second; the third is 10 km near to the fourth that it is to the second.

Can you calculate the distance between the fourth and the first village ?

Asked by Neha on 23 Mar 2023


There are two insects on a tile. Insect X is sitting on one side of the tile (point A) and Insect Y is sitting opposite on the other side of the tile (point B). Now both of them decide to change their position and thus X starts crawling to point B and Y starts crawling to point A. When they meet and pass each other in between, X takes 20 seconds to reach B and Y takes just 5 seconds to reach A.

Can you calculate the total time each of the insects took to change their positions?

Asked by Neha on 25 Feb 2026

If a zookeeper had 100 pairs of animals in her zoo, and two pairs of babies are born for each one of the original animals, then (sadly) 23 animals don’t survive, how many animals do you have left in total?

Asked by Neha on 05 Aug 2025

A 52% bias toss for head using the 51% tail bias coin was done to obtain a fair result.

Can you find how bias is the floor in this case?

Asked by Neha on 15 Feb 2023


If 5 cats catch 5 mice in 5 minutes, how long will it take one cat to catch a mouse?

Asked by Neha on 22 Mar 2022

Hot Articles

Amazing Facts

Crossword puzzles

In the 1920s, people feared that crossword puzzles would contribute to illiteracy.