The Vedic Sutra Yavadunam means “By the deficiency”. It can be explained as how much something differs from the whole. By whole, we are referring to the nearest multiple of 10.
For example, 29 is 1 less than the nearest whole number 30, 68 is 2 less than the nearest whole number 70.
If we combine the deficiency and the completion (i.e. Sum to Ten), then it becomes very easy to find the sum of 2 or more numbers. This method is also called “By Addition and By Subtraction”.
Let us understand this with an example: 38+53 = ?
- 38 is 2 less than 40, so we take 2 from 53 and add this 2 with 38 to make 40.
- now the sum becomes 40 + 51 = 91, which is comparatively easy to add than the original sum.
From the above example, you can notice that adding any number with any multiple of 10 is very easy. So, the main aim is to try to complete the whole by adding the deficiency and then finding the result.
Let’s us practice few more sums:
a 39 + 15 b 57 + 13 c 46 + 6 d 28 + 26 e 79 + 16 f 38 + 27
g 7 + 57 h 69 + 24