Thursday, September 20, 2012

Finding 55 percent of a number

Follow the following Steps:
  1. Choose a 2-digit number.
  2. Multiply the number by 11.
  3. Divide by 2.
  4. Move the decimal point one place to the left.

   Example-1:

  1. If the number selected is 81:
  2. Multiply by 11: 11 × 81 = 891
    right digit is 1
    next digit to left is 1 + 8 = 9
    last digit to left is 8
  3. Divide by 2: 891/2 = 445.5
  4. Move the decimal point one place to the left: 44.55
  5. So 55% of 81 = 44.55.
    Example-2:
  1. If the number selected is 59:
  2. Multiply by 11: 11 × 59 = 649
    right digit is 9
    next digit to left is 9 + 5 = 14 (use the 4 and carry 1)
    last digit to left is 5 + 1 = 6
  3. Divide by 2: 649/2 = 324.5
  4. Move the decimal point one place to the left: 32.45
  5. So 55% of 59 = 32.45.

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