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mathematics skills

Are you ready to give your mathematics skills a boost? These simple math tricks can help you perform calculations more quickly and easily. They also come in handy if you want to impress your teacher, parents, or friends.

01



  2. The Answer Is 2
  3. Think of a number.
  4. Multiply it by 3.
  5. Add 6.
  6. Divide this number by 3.
  7. Subtract the number from Step 1 from the answer in Step 4.

The answer is 2.



  1. Same Three-Digit Number
  2. Think of any three-digit number in which each of the digits is the same. Examples include 333, 666, 777, and 999.
  3. Add up the digits.
  4. Divide the three-digit number by the answer in Step 2.

The answer is 37.



  1. Six Digits Become Three
  2. Take any three-digit number and write it twice to make a six-digit number. Examples include 371371 or 552552.
  3. Divide the number by 7.
  4. Divide it by 11.
  5. Divide it by 13.

The order in which you do the division is unimportant!

The answer is the three-digit number.

Examples: 371371 gives you 371 or 552552 gives you 552.

  1. A related trick is to take any three-digit number.
  2. Multiply it by 7, 11, and 13.

The result will be a six-digit number that repeats the three-digit number.

Example: 456 becomes 456456.



          

          The 11 Rule

          This is a quick way to multiply two-digit numbers by 11 in your head.

  1. Separate the two digits in your mind.
  2. Add the two digits together.
  3. Place the number from Step 2 between the two digits. If the number from Step 2 is greater than 9, put the one's digit in the space and carry the ten's digit.

Examples: 72 x 11 = 792.

57 x 11 = 5 _ 7, but 5 + 7 = 12, so put 2 in the space and add the 1 to the 5 to get 627



 Memorizing Pi

To remember the first seven digits of pi, count the number of letters in each word of the sentence:

"How I wish I could calculate pi."

This becomes 3.141592.



  1. Contains the Digits 1, 2, 4, 5, 7, 8
  2. Select a number from 1 to 6.
  3. Multiply the number by 9.
  4. Multiply it by 111.
  5. Multiply it by 1001.
  6. Divide the answer by 7.

The number will contain the digits 1, 2, 4, 5, 7, and 8. 

Example: The number 6 yields the answer 714285.




Multiply Large Numbers in Your Head

To easily multiply two double-digit numbers, use their distance from 100 to simplify the math:

  1. Subtract each number from 100.
  2. Add these values together.
  3. 100 minus this number is the first part of the answer.
  4. Multiply the digits from Step 1 to get the second part of the answer.


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