Class 6 | Mathematics | Chapter 2|
Whole Numbers | Exercise 2.3
Question 1: Which of the following will not represent zero:
(a) 1 + 0
(b) 0 x 0
(c) 0 ÷ 2
(d) (10- 10)/2
Answer: (a) [1 + 0 is equal to 1]
Question 2: If the product of two whole numbers is zero, can we say that one or both of them will be zero? Justify through examples.
Answer 2: Yes, if we multiply any number with zero the resultant product will be zero.
Example: 2 x 0 = 0,
5 x 0 = 0,
9 x 0 = 0
If both numbers are zero, then the result also be zero. 0 x 0 = 0
Question 3: If the product of two whole number is 1, can we say that one or both of them will be 1? Justify through examples.
Answer: If only one number be 1 then the product cannot be 1.
Examples: 5 x 1 = 5,
4 x 1 = 4, 8 x 1 = 8
If both number are 1, then the product is 1 1 x 1 = 1
Question 4: Find using distributive property:
(a) 728 x 101
(b) 5437 x 1001
(c) 824 x 25
(d) 4275 x 125
(e) 504 x 35
Answer: (a) 728 x 101
= 728 x (100 + 1)
= 728 x 100 + 728 x 1
= 72800 + 728
= 73528
(b) 5437 x 1001
= 5437 x (1000 + 1)
= 5437 x 1000 + 5437 x 1
= 5437000 + 5437
= 5442437
(c) 824 x 25
= 824 x (20 + 5)
= 824 x 20 + 824 x 5
= 16480 + 4120
= 20600
(d) 4275 x 125
= 4275 x (100 + 20 + 5)
= 4275 x 100 + 4275 x 20 + 4275 x 5
= 427500 + 85500 + 21375
= 534375
(e) 504 x 35
= (500 + 4) x 35
= 500 x 35 + 4 x 35
= 17500 + 140
= 17640
Question 5: Study the pattern: 1 x 8 + 1 = 9;
12 x 8 + 2 = 98;
123 x 8 + 3 = 987
1234 x 8 + 4 = 9876;
12345 x 8 + 5 = 98765
Write the next two steps. Can you say how the pattern works?
Answer: 123456 x 8 + 6 = 987654
1234567 x 8 + 7 = 9876543
Pattern works like this:
1 x 8 + 1 = 9
12 x 8 + 2 = 98
123 x 8 + 3 = 987
1234 x 8 + 4 = 9876
12345 x 8 + 5 = 98765
123456 x 8 + 6 = 987654
1234567 x 8 + 7 = 9875643