RS Aggarwal Class 6 Math Third Chapter Whole Numbers Exercise 3B Solution

EXERCISE 3B

(1) Fill in the blanks to make each of the following a true statement:

(i) 458 + 639= 639 + 458

(ii) 864 + 2006= 2006 + 864

(iii) 1946 + 984= 984 + 1946

(iv) 8063 + 0= 0 + 8063

(v) 53501 + (574 + 799)= 574 + (53501 + 799)

(2) Add the following numbers and check by reversing the order of the addends:

(i) 16509 + 114= 16623.

(ii) 2359 + 548= 2907.

(iii) 19753 + 2867= 22620.

(3) Find the sum: (1546 + 498) + 3589.

Also, find the sum: 1546 + (498 + 3589).

Ans: 5633; 5633;

Are the two sums equal?

Ans: Yes.

State the property satisfied.

Ans: associative law of addition of whole numbers.

(4) Determine each of the sums given below using suitable rearrangement.

(i) 953 + 707 + 647= 2307.

(ii) 1983 + 647 + 217 + 353= 3200.

(iii) 15409 + 278 + 691 + 422= 16800.

(iv) 3259 + 10001 + 2641 + 9999= 25900.

(v) 1 + 2 + 3 + 4 + 96 + 97 + 98 + 99= 400.

(vi) 2 + 3 + 4 + 5 + 45 + 46 + 47 + 48= 200.

(5) Find the sum by short method:

(i) 6784 + 9999= 16783.

(ii) 10578 + 99999= 110577.

(6) For any whole numbers a, b, c is it true that (a + b) + c= a + (c +b)? Give reasons.

Ans: Yes, by associative and commutative laws of addition of whole numbers.

(8) Write (T) for true and (F) for false for each of the following statements:

(i) The sum of two odd numbers is an odd number.

Ans: F.

Statement: The sum of two odd numbers is always an even number. Example: 1+1= 2.

(ii) The sum of two even numbers is an even number.

Ans: T.

(ii) The sum of an even number and an odd number is an odd number.

Ans: T.