# 5 TED Talks you must show your maths class

Looking for a way to breathe new life into your maths lessons? Then we suggest you check out the excellent maths riddle videos made by the team over at TED-Ed. With their charming animation and engaging storytelling style, not only are these videos entertaining; they are perfect for teachers wanting to sharpen their students’ problem-solving skills. For your viewing pleasure, here are Whizz Education’s top five TED-Ed maths videos!

### 1. The Green-Eyed Logic Puzzle

This is an intriguing logic puzzle that tells the tale of a daring escape staged by a group of 100 people held prisoner on a desert island by a mad dictator. It introduces students to philosopher David Lewis’ concept of common knowledge and the role it plays in problem-solving, although that isn’t the most important lesson. More significantly, it also teaches students that where maths is concerned, there is always more than meets the (ahem) eye and that questions which seem unsolvable on the surface can be worked out if they are prepared to think through it systematically. We recommend showing this to students in Years 5 and 6.

### 2. Crossing the Bridge

This is a simple problem that is accessible to primary school students of all ages due to its low floor entry point and high ceiling potential. The objective is to get four people across a rickety bridge in 17 minutes or face the wrath of some pretty fearsome zombies. As you’ll see in the video, however, this task is far from straightforward. At its core, this is a simple addition problem that is also easy to frame and to take initial attempts at, but it requires a fair amount of experimentation. We think this problem would be fun to recreate – perhaps ask your students to try to figure out how to cross the playground within a time limit rather than over a rickety bridge! Try it out as early as Year 2.

### 3. The Prisoner Hat Riddle

10 humans are abducted by a group of aliens who intend to eat them – unless the humans prove themselves to be highly logical! The humans are placed in single file, tallest to shortest and are each given either a black or a white hat. Starting from the back, they must guess which colour hat they are wearing and they can only make one mistake between them or they’re alien chow! How will they do it? Watch the video! The key lessons here relate to creating a code and following logical patterns. The solution relies on a nifty application of parity (odds vs evens). Aside from the concepts, the problem also serves as a great lesson in teamwork: another challenge worth recreating in class. Try calling 10 students to the front and test whether they’d be able to escape the aliens. Great for Years 3 to 5.

### 4. The Dark Coin Riddle

This one will be of particular interest to the adventurers in your class! In this scenario, an explorer manages to locate a dungeon full of valuable coins. Unfortunately, the coins are guarded by a wizard who will only let the explorer leave with the loot if he passes a tricky test. The concept explored in this video is ‘complementary events’ – it incorporates a bit of algebra too, so save this one for the older children who are preparing for the transition to secondary school.

### 5. The Passcode Riddle

Another problem involving a dystopian future and people being trapped! (A theme seems to be emerging here). This time three resistance fighters are captured by tyrannical rulers. They will be fed to mutant salamanders unless they can guess the three-digit code needed to deactivate an electrified door using the three maths-based clues provided. This is a great question for teachers looking to exercise their students’ maths fluency and mix it up with a touch of problem-solving as it incorporates addition, multiplication and lots of calculation! We’d recommend trying this with students in Years 4 and 5.

## Want even more engaging maths material for your students?

Look no further than the Maths-Whizz Tutor! With Maths-Whizz’s colourful animations, exercises and exciting rewards, your students will love maths in no time – it’s the perfect online maths service for schools!