To square any number ending in 5, follow this simple trick! The last two digits of the product will always be 25. The remaining first digits can be found by multiplying the first digits of the original number by their next consecutive number.

For example, lets take the number 75:

• The last two digits are 25.
• The first digit is 7. Multiply it by its next consecutive number: 7 × 8 = 56.
• Combine the result: 5625 is the square of 75!

Try it with 35:

• The last two digits are 25.
• The first digit is 3. Multiply it by its next consecutive number: 3 × 4 = 12.
• Combine the result: 1225 is the square of 35!

This works with all numbers(including more than 2 digits)