The Hidden Faces Dice Trick
Ready to dazzle your pupils with a mind-bending maths trick? The Hidden Faces Dice Trick will leave your class spellbound. It's the perfect blend of magic and mathematics!
Setting the Stage
1
Gather Your Props
Grab three dice and a willing volunteer. Bigger dice work best for visibility.
2
Create Suspense
Turn your back dramatically. Ask your helper to stack the dice secretly.
3
Sneak a Peek
Glance quickly at the top die. Remember this number - it's your secret weapon! (Turn around "Are you done, yet, Oh Sorry")
The Magical Instructions
1
Sum the Hidden Faces
Ask your helper to add the bottom face of the first die to the top of the second.
2
Continue the Pattern
They should add the bottom of the second die to the top of the third.
3
Final Touch
Lastly, ask them to add the bottom face of the third die.
The Maths Behind the Magic
Opposite Faces
On a standard die, opposite faces always sum to 7. This is the key!
Three Dice Magic
With three dice, the sum of all hidden faces is always 21. It's maths magic!
Your Secret Formula
Subtract the top face you peeked at from 21. That's the hidden sum!
The Big Reveal
1
Build Suspense
Ask your helper to announce their calculated sum. Pause for effect!
2
Reveal Your Prediction
Write your prediction on the board. Watch jaws drop as it matches perfectly!
3
Explain the Magic
Show how you calculated it instantly using your peek and the 21 rule.
Numerical example
Let's say the following are the numbers: The top face of the first die is 4. (Remember, this is your secret weapon - don't reveal it yet!). The Bottom face of die one is 3, the top face of die two is 6 and the bottom face is 1. The top face of die three is 3 and the bottom face is 4.
The bottom of the first die is 3, and the top of the second die is 6. So, your helper adds 3 + 6 = 9.
Then, they add the bottom of the second die (1) to the top of the third die (3). This gives them 1 + 3 = 4.
Finally, they add the bottom face of the third die, which is 4.
The total sum they calculate is 9 + 4 + 4 = 17. You already know this from (21-4)
Classroom Applications
Mental Maths Practice
Use this trick to make addition and subtraction more engaging. Students will love the challenge!
Probability Discussions
Explore why opposite faces always sum to 7. Discuss dice design and fairness.
Problem-Solving Skills
Challenge students to figure out why the trick works. It's a great critical thinking exercise!
Variations and Extensions
Different Dice
Try the trick with differently numbered dice. Discover how it changes the math behind the magic!
Number Grid
Use a number grid (1-6) and ask students to find patterns when adding opposite faces on dice. It's a fun way to visualize number relationships!
Dice Games
Challenge students to create new dice games incorporating the 'sum to 7' rule. This promotes problem-solving and game design skills!
Mastering the Performance
View the video below to see a demonstration of this trick.