FINDING CUBE OF NUMBERS

ANY  TWO  DIGIT  NUMBER

With this method we can find cube of any two digit number.
We have to write the numbers in four places

• Write cube of first digit of the given number in the first place and cube of second digit of the given number in the last(4th) place
• Take square of first digit and multiply by the second digit and keep the result in the 2nd place
• Then take square of second digit and multiply by the first digit and keep the result in the 3rd place
• Double the 2nd and 3rd place numbers and add to 2nd and 3rd place numbers respectively
• Now add all the numbers to get the cube of the given number Let us take an example and understand this method.

• We find cube of 26
  ⇒ First write cube of 2 in the first place and cube of 6 in the last place
  8     ( )      ( )       216
• ⇒ Take square of 2 and multiply by 6 and keep the result in the 2nd place 2 ²  × 6 = 24
  8    24      ( )       216
• ⇒ Take square of 6 and multiply by 2 and keep the result in the 3rd place 6 ² × 2 = 72
  8     24      72      216
• ⇒ Now double the middle numbers and add
  8              24               72              216
  48              144
  (9)         (23)            (21)                          ← Carry

17            5                 7                 6

∴ 26³ = 17576