MATHS TRICK 1
It is difficult to study multiplication table up to 9 for some students. An important study reveals that more than 50 per cent of the student body , is away from mathematics.
Here is your opportunity to acquire multiplication table from 11 to 19.
Study carefully and be a master of multiplication tables in seconds and Master of Maths later.
Example I . 11 x 12
Step 1 : 11 + 2 = 13
OR 12 + 1 = 13
( The first number is added to the unit digit of second number (11+2) OR Second number is added to the unit digit of first number (12+1) )
Both give the same result
Step 2 : The result is multiplied by 10
13 x 10 = 130
Step 3 : Product of the unit digits of the given numbers.
1 x 2 = 2 (1 of 11 and 2 of 12)
Step 4 : Add the results of Step 2 and Step 3
130+2 = 132
11 x 12 = 132
Example 2
16 x 17
Step 1 : 16 + 7 = 23 (OR 17+6 =23)
Step 2 : 23 x 10 = 230
Step 3 : 6 x 7 = 42 (product of unit digits)
Step 4 : 230+ 42 = 272
16 x 17 = 272
Example 3.
18 x 19
1 8 + 9 = 2 7 0
--
8 x 9 = 7 2
--------
3 4 2
====
18 x 19 = 342
Example 4.
1 3 x 1 9
1 3 + 9 = 2 2 0
9 x 3 = 2 7
---------
2 4 7
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Brilliant, you solved the puzzle!
No need of using pen and paper. You can multiply any number between 11 and 19 within 5 seconds.
MATHS TRICK 2
If one of the number is decimal
Example1 : 17.5 x 11
17.5 + 1 = 18.5
18.5 x 10 = 185
7.5 x 1 = 7.5
185+ 7.5 = 192.5
Example 2. 16 x 12.5
16 + 2.5 = 18.5 ----185 +
6 x 2.5 = 15
-----
200
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Exercise
1. 12 x 19
2. 13 x 13.5
3. 15 x 16.5
4. 19 x 14
5. 17 x 14.5
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