By Ariel Marcy, 12 March 2024
Lavonne is testing a secret code with her friend Jack. First, she picks 3 different secret numbers between 1 and 9. Then she finds the sum of each pair of numbers. Lavonne wants to know if Jack can figure out the original secret numbers just from the sums. If she tells him that the sums are 7, 12, and 13, can Jack recreate the secret numbers?
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By Ariel Marcy, 10 January 2024
Holly loves drawing with coloured pencils and her favourite colours have been sharpened a lot. She realises that her most favourite colour, rose, is exactly 3 centimetres long. She measures her other pencils and discovers that the teal pencil is exactly 4 centimetres, and the almond pencil is exactly 6 centimetres (cm). What lengths from 1-10 cm can Holly make with her pencils?
By Ariel Marcy, 14 December 2023
In 2023, Double Helix readers busted a bunch of brainteasers! Here are the tippy-top, most popular puzzles of the year.
By Ariel Marcy, 6 December 2023
Can you find a different set of 5 positive whole numbers with the same stats?
By Ariel Marcy, 21 November 2023
The Great Barrier Reef is one of Earth’s 7 natural wonders. We’re wondering if you’ll be a natural at this quiz! Wade into the Reef’s fantastic ecology and aim for a dive out of five.
By Ariel Marcy, 14 November 2023
Difficulty: Fun Ellen has a set of 6 weights that come in pairs. One pair is a magical set of negative weights (think helium balloons that take weight away). 2 of the weights are 1 kilogram each, 2 of the weights are 5 kilograms each, and the 2 magical weights are -3 kilograms each. Ellen […]
By Ariel Marcy, 6 November 2023
Difficulty: Fun Triangular numbers are numbers that can be formed into a triangle. For example, 3 is a triangular number with 2 dots on the bottom row and 1 dot on top row forming an equilateral triangle of 3 dots. 6 is the next triangular number with 3 dots on the bottom, 2 dots in […]
By Ariel Marcy, 23 October 2023
Difficulty: Tricky Anas is making a map of his friend group. In his map, each circle is a person. A line joins 2 circles if and only if those 2 people are friends. Using the clues below, can you figure out who goes where on the map? 1. Anas has 3 friends: Ruth, Mitra, and […]
By Ariel Marcy, 4 October 2023
Difficulty: Tricky Ahmad’s computer scientist mother gives him a binary stopwatch that counts minutes using only 1’s and 0’s – just like a computer! The binary stopwatch has 6 placeholders where the 1’s and 0’s appear. When the binary stopwatch is reset, all the placeholders are zeros. Ahmad finds a regular stopwatch, resets both stopwatches, […]
By Ariel Marcy, 27 September 2023
Difficulty: Tricky You have 2 glasses, each filled with 100 millilitres (ml) of soda. One contains cola and one contains orange soda. First, you take a spoonful of cola and mix it into the orange soda. Next, you take an equal spoonful of the orange-cola mixture and put it into the glass of cola. Which […]
12 months, 8 issues
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Perfect for ages 8 – 14
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