Difference of Squared Numbers

Many times you will subtract squared numbers so this trick will help make your life easier.

Look at the math problem 54² - 51² = ? .

• Add the two numbers together..
  • 54 + 51 = 105.
• Subtract the right number from the left number.
  • 54 - 51 = 3.
• Multiply these two answers.
  • 105 x 3 = 315.

ANSWER is 315.

Look at the math problem 34² - 21² = ? .

• Add the two numbers together..
  • 34 + 21 = 55.
• Subtract the right number from the left number.
  • 34 - 21 = 13.
• Multiply these two answers.
  • 55 x 13 = 715.

ANSWER is 715.

Watch the math video below for a detailed explanation!

Practice Math Problems

1. What does 63² - 57² = ?
2. What does 25² - 21² = ?
3. What does 72² - 64² = ?
4. What does 33² - 41² = ?
5. What does 13² - 23² = ?