Easy Trick to Square Numbers Ending in 5

Squaring numbers ending with 5 can seem like a time-consuming task, but there’s a simple mental math trick that can help you do it in seconds! Whether you’re preparing for competitive exams, brushing up on your arithmetic skills, or just love math tricks, this method will make your calculations faster and more efficient.

Why Learn This Trick?

• Saves time in exams and quick calculations
• Improves mental math skills
• Eliminates the need for calculators for simple calculations

The Simple Trick to Square Numbers Ending in 5

Follow these easy steps to square any number ending in 5:

Step-by-Step Method:

1. Identify the number without the last digit (5).
   • Example: For 25, remove the 5 → You are left with 2.
   • Example: For 75, remove the 5 → You are left with 7.
2. Multiply this number by its next consecutive number.
   • Example: 2 × 3 = 6
   • Example: 7 × 8 = 56
3. Attach ’25’ to the result.
   • Example: 625 (for 25²)
   • Example: 5625 (for 75²)

That’s it! You’ve successfully squared the number in seconds.

Examples for Better Understanding

Why Does This Trick Work?

Mathematically, any number ending in 5 can be represented as (10x + 5). Expanding the square:

(10x+5)2=100×2+100x+25(10x + 5)^2 = 100x^2 + 100x + 25

Rearranging:

x(x+1)×100+25x(x+1) × 100 + 25

This proves why multiplying the first digit by its next number and adding 25 always works!

Practice Problems

Try these on your own and check your answers:

1. 45² = ?
2. 85² = ?
3. 105² = ?
4. 125² = ?

Conclusion

This squaring trick is a fantastic mental math shortcut that can boost your speed and confidence in calculations. Keep practicing, and soon you’ll be squaring numbers ending in 5 effortlessly!