Class 6 NCERT bridge course Answers Activity W1.3 The Magic Number Trick!

 Activity W1.3 

The Magic Number Trick!

 Think of a number;

 multiply it by 2; 

add 6; 

take half of the number; 

 subtract 1; 

subtract the number thought of;

 I predict you now have 2. 

 Let the students play this game in pairs. 

Ask them to discuss and find out the trick behind it. 

 Encourage them to come up with similar such tricks

Activity W1.3 – The Magic Number Trick!

“No Matter What Number You Choose… I Predict the Answer!”

Objective:

To explore number patterns and reasoning by using arithmetic operations that lead to a surprising fixed result—the number 2—every time!

The Magic Trick Steps:

1. Think of any number → Let’s call it x

2. Multiply it by 2 → Result = 2x

3. Add 6 → Result = 2x + 6

4. Take half of it → Result = (2x + 6) ÷ 2 = x + 3

5. Subtract 1 → Result = x + 2

6. Subtract the number you started with (x)
   Result = (x + 2) – x =  2

Example:

Let's start with 7

1. Start with: 7

2. Multiply by 2 → 7 × 2 = 14

3. Add 6 → 14 + 6 = 20

4. Half of 20 = 10

5. Subtract 1 → 10 – 1 = 9

6. Subtract original number → 9 – 7 =  2

 It works!

Why This Trick Works (The Math Behind It):

Let the number be x

• Multiply by 2 → 2x

• Add 6 → 2x + 6

• Half → (2x + 6)/2 = x + 3

• Subtract 1 → x + 2

• Subtract x → Answer is always 2

It’s algebra magic!

Pair Activity:

• One student chooses a number and follows the steps.

• The partner predicts the answer (2), then checks it.

• Swap roles and repeat with different numbers.

Challenge Students:

• Can you create a new trick that always results in another fixed number (like 5 or 10)?

• Use operations like: add, subtract, double, triple, halve, etc.

• Try writing your own step-by-step magic pattern!

Illustrative Image: Magic Number Trick Flowchart

Shows the trick path where any number always leads to 2.