**(1)** **Find the sum by suitable rearrangement:**

**(a) 837 + 208 + 363**

**Sol. **(Note** – **In order to make the process convenient, making group of two such numbers whose addition will give 0 in one’s place.)

Here, we will make group of 837 and 363 because the sum of their one’s digit i.e. 7 + 3 = 10

= (837 + 363) + 208

= 1200 + 208 **= 1408 Ans**

**(b) 1962 + 453 + 1538 + 647**

**Sol. **(Note** – **In order to make the process convenient, making group of two such numbers whose addition will give 0 in one’s place.)

Here, we will make group of 453 and 647 because the sum of their one’s digit i.e. 3 + 7 = 10

Also, we will group 1962 and 1538 because the sum of their one’s place i.e. 2 + 8 = 10

(1962 + 1538) + (453 +647)

= 3500 + 1100

= (35 x 100) + (11 x 100)

= (35 + 11) x 100 (Taking 100 common)

= 46 x 100

** = 4600 ** **Ans.**