Posted by admin on June 24th, 2009
Multiplying by Altering
This trick can be used when one of the multiplicants end in 9. The trick is to add 1 to the number that ends in 9 and then multiplying it with the second multiplicant.
Subtract the second multiplicant from the above result.
Have fun with the trick
19 x 5 = ??
Answer 95
Let’s try another one:
329 x 4 = ??
Time for you to try
| 39 |
x |
2 |
= |
|
| 59 |
x |
4 |
= |
|
| 79 |
x |
3 |
= |
|
| 89 |
x |
5 |
= |
|
| 99 |
x |
7 |
= |
|
Posted by admin on May 28th, 2009
Multiply up to 20 x 20 in your mind.
With this trick, you will be able to multiply any two numbers, from 11 to 19 in your mind quickly, without the use of a calculator.
Have fun with the trick
15 x 13
Always place the larger number of the two on top in your mind. Cover 15 and “3″ from 13 below. Those covered numbers are all you need.
First add 15 + 3 = 18
Add a zero behind it (multiply by 10) to get 180.
Multiply the covered number “3″ and the single digit above it i.e “5″ to get 15 (3 x 5 = 15)
Add 180 + 15 = 195
Time for you to try
| 14 |
x |
12 |
= |
|
| 13 |
x |
19 |
= |
|
| 17 |
x |
13 |
= |
|
| 16 |
x |
12 |
= |
|
| 18 |
x |
14 |
= |
|