Wrap Math :: Multiplication Tricks Summary-(1)

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