In Vedic math multiplication is a vast subject. Choosing the right method for a particular multiplication problem is a skill one needs to develop. Here are some special multiplication methods that can really improve your speed of calculation.
First, how to multiply any number by a two-digit number ending in 9 like 29, 39, 49.
Example: 32 x 19
Step 1: 19 is close to 20. So we multiply the given number by 20.
32 x 20 = 640
Step 2: 20 times is one time more than we needed so we need to subtract 32 once to get the right answer. 640 – 32 = 608
Answer: 608
Now let us try to do it mentally with another example: 45 x 69
First, multiply 45 x 70 = 3150
Second, 3150 – 45= 3105
Answer: 45 x 69 = 3105
Let us look at another method. If one of the numbers is 9, 99, 999, the product is easy to find.
Example: 53 x 99
First, 53 x 100 = 5300
Next, 5300 - 53 = 5247
Answer: 53 x 99 = 5247
Try 62 x 999 =
62 x 1000= 62000
62000 – 62 = 61938
62 x 999 = 61938
Next let us look at an interesting method of multiplication by factors, where you can multiply by factors to arrive at the answer.
For example, multiplication by 12 can be easily achieved as we know that 12 = 3 x 4. To multiply any number by 12, we can first multiply it by 3 and then that answer by 4.
Examples:
48 x 12 = 48 x (3 x 4)
48 x 3 = 144
144 x 4 = 576
81 x 45 = (9 x 9) x (9 x 5)
9 x 9 x 9 = 729
729 x 5 = 3645
If the question is 38 x 25, how can you do it?
Here is yet another method
First, 38 x 100 = 3800
Next, 3800 / 4 = 950
We know that 100 / 4 = 25. So instead of multiplying by 25 we multiply by 100 and divide by4.
Tip of the week: Choose the right method for different problems