Subtracting Near a Base

The Vedic Sutra “Sankalana vyavakalanabhyam” means “By Addition and by Subtraction”. Let us understand this sutra with an example.

68 – 29 = ?

Here, 29 is 1 less than the nearest whole number 30, so :

• Step 1: Increment 29 by 1 to make 30
• Step 2: Increment 68 by 1 to make 69 to nullify the increment of Step 1

The above can be represented in expression as 68 – 29 = (68+1) – (29+1) = 69 – 30 = 39.

Isn’t it easier to subtract 30 from 69 than 29 from 68?

Let us do it mentally with another example:

53 – 29 = ?

 

 

 

 

 

In short, when subtracting a number close to a multiple of 10, just subtract from the multiple of 10 and correct the answer accordingly.

Let’s us practice few more questions:

a  38 – 19        b  57 – 28         c  46 – 8         d  95 – 27       e  74 – 28         

f  33 – 29         g  217 – 59          h  176 – 109

⇐ Topic 2: Subtraction

Practice Test ⇒