Wrap Math :: Multiplication Tricks Summary-(1)

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How to multiply with easy and quick will be explained.
If you follow me, then you can solve all the problems below.

Just remember base, which means a power of 10, and a series of process.
Let's solve the example, 98 X 97

  1. The base shall be 100.
  2. You shall subtract 100 each from 98 and 97, which would be -2, -3.
  3. You shall position numbers like the followed.
  4. On the left, you shall position the value of 98 + (-3) or 97 + (-2) which is the diagonal summation.
  5. On the right, you shall position the value of (-2) X (-3).
    The digits on the right must be equal to the number of zeros in base.

       98       -2
       97       -3
      -------------
       95   |   06

Do Exercise

  • 9996 X 9997 = ?
     Base : 10,000
      9996          -4
      9997          -3
     --------------------
      9993   |   0012

  • 699 X 998
     Base : 1,000
      699        -301
      998        -2
     ------------------
      697   |   602

  • 1002 X 1004
     Base : 1,000
      1002         +2
      1004         +4
     --------------------
      1006   |   008

  • 1301 X 1004
     Base : 1,000
      1301         +301
      1004         +4
     --------------------
      1305   |   1204 → wrong
      1305   |
            1   |   204
     --------------------
      1306   |   204

  • 1007 X 998
     Base : 1,000
      1007          +7
       998           -2
     --------------------
      1005   |   (-14)
     --------------------
      1004   |   986 ← 1000-14
Wrap Math :: Multiplication Tricks Summary-(1) | Ecency