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Learn Vedic Math

Square numbers ending in 5

From the sutra Ekādhikena Pūrveṇa, By one more than the one before, in Bharati Krishna Tirtha's 1965 book Vedic Mathematics. Deep dive into the sutra

Try it with your numbers

When to use it

Any number that ends in 5: 35², 85², 115².

The idea

Take the part before the 5, multiply it by one more than itself, then write 25 after it.

Worked example: 65²

  1. 652The part before the 5 is 6.
  2. 6 × 7 = 42One more than 6 is 7. Multiply: 6 × 7 = 42.
  3. 42 | 25 = 4225Write 25 on the right. 65² = 4225.

Practice this trick

All 15 speed tricks, each with its calculator. The speed tricks use sutras from Bharati Krishna Tirtha's 1965 book Vedic Mathematics; the lessons, problems and pictures here are our own.