# Blog

## Biggest prime number found!

By Evrim Yazgin, 31 October 2024

The biggest ever prime number has just been found and it’s absolutely massive. It’s a number with more than 41 million digits. That means, if you were to type it out in size 12 font, it would be more than 8,000km long! That’s about the distance from Melbourne to Tokyo.

Categories:

## Brainteaser: Beat the bell

By Ariel Marcy, 9 October 2024

Right before the bell rings, Jeri’s teacher throws up a problem on the board: “I’m thinking of a number. When I add its digits together and multiply by seven, I get the number I first thought of. The number is under 40.” Can you help Jeri find the number before class is dismissed?

Categories:

## Brainteaser: Drilling the distance

By Ariel Marcy, 10 September 2024

A team of geologists are using the latest technology to drill into the Earth’s ocean floor and look at the rock underneath! They manage to drill a total of 1250 metres (based on a recent true story!). But the drilling gets harder the deeper they get.

Categories:

## Wrong seat brainteaser

By David Shaw, 29 August 2024

Eight people come together for a very important meeting. How many ways can just one person sit in the wrong chair?

Categories:

## Brainteaser: Animal equations

By Ariel Marcy, 13 August 2024

In this puzzle, each Aussie animal stands for a number. Each animal represents the same number throughout the puzzle. Can you use the first three mathematical equations to figure out the answer to the last equation?

Categories:

## Brainteaser: Batteries

By Ariel Marcy, 30 July 2024

A team of engineers have invented a new, stretchy battery that is clear. Another team have invented a jelly-like battery that is rainbow coloured. Both teams want to compare how long their batteries last to a regular, silver AA battery.

Categories:

## Brainteaser: Walkin’ the perimeter

By Ariel Marcy, 16 July 2024

Lavonne is a security guard who has to walk around the outside of an L-shaped building. She knows the length of the longest sides, 200 metres and 140 metres. She also knows the shape of the building and that each of the angles are 90 degrees. What is the building’s perimeter?

Categories:

## Brainteaser: Chessboard challenge

By Ariel Marcy, 4 July 2024

One day, Rumi’s chess club coach asks her, “how many squares are on a chess board?” Rumi replies, “That’s easy, the board is 8 by 8, so there are 64 squares!” Her coach smiles, “What about the larger squares made up of smaller squares? The board is an 8 by 8 square after all!” How many squares are on a chess board?

Categories:

## Brainteaser: Triangle plus

By Ariel Marcy, 18 June 2024

The teacher challenges Becki and her classmates to find three bottom numbers that follow the pattern and add up to 15. Becki is pretty sure that there are multiple solutions, where the numbers along the bottom appear in different orders. If she keeps at it, how many different solutions will Becki find?

Categories:

## Brainteaser: Sharing so much chocolate

By Ariel Marcy, 29 May 2024

Anamaria and Chen are two friends who toured a magical chocolate factory! They both get enormous amounts of chocolate and they want to share it evenly between them. Anamaria gets 1,574,936 squares of chocolate and Chen gets 3,569,321 squares of chocolate. Without using a calculator, can you tell if it is possible for them to share the chocolate between them without breaking any squares?

Categories:

## Why choose the Double Helix magazine for your students?

Perfect for ages 8 – 14

Developed by experienced editors

Engaging and motivating

*84% of readers are more interested in science

Engaging students voice