Whole Numbers
Exercise 2.3
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.
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.
If the product of to whole numbers is zero, then either any one of them is zero or both of them are zero.
2 X 0 = 0
0 X 5 = 0
0 X 0 = 0
3). If the product of two whole numbers is 1, can we say that one or both of them will be 1? Justify through examples.
The product of two whole numbers is 1 only when the two whole numbers are 1.
4). Find using the distributive property.
a). 728 X 101
728 X 101 = 728 X (100+1)
= 728 X 100 + 728 X 1
= 72800 + 728
= 73528
728 X 101 = 73528
b). 5437 X 1001
5437 X 1001 = 5437 X (1000+1)
= 5437 X 1000 + 5437 X 1
= 5437000 + 5437
= 5442737
5437 X 1001 = 5442737
c). 824 X 25
824 X 25 = 824 X (20+5)
= 824 X 20 + 824 X 5
= 16480 + 4120
= 20600
824 X 25 = 20600
d). 4275 X 125
4275 X 125 = 4275 X (100+20+5)
= 427500 + 85500 + 21375
= 534375
4275 X 125 = 534375
e). 504 X 35
504 X 35 = 504 X (30+5)
= 504 X 30 + 504 X 5
= 1512 + 2520
= 4032
504 X 35 = 4032
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?
(Hint: 12345 = 11111 + 1111 + 111 + 11 + 1).
The next two steps are
123456 X 8 + 6 = 987654
1234567 X 8 + 7 = 9876543
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