Question 2 Using divisibility tests, determine which of the following numbers are divisible by 4; by 8: (a) 572 (b) 726352 (c) 5500 (d) 6000 (e) 12159 (f) 14560 (g) 21084 (h) 31795072 (i) 1700 (j) 2150
Class 6 - Math - Playing with Numbers Page 57
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Divisibility by 4
A number will be divisible by 4 if the number formed by its tens and ones digit(Last two digits) is divisible by 4.
If its ones place is odd then it is not divisible by 4
If its last 2 digits have 0 then it is divisible by 4
.Divisibility by 8
A number will be divisible by 8 only when the number formed by hundreds tens and ones digit( last 3 digits) is divisible by 8.
If its ones place is odd then it is not divisible by 8.
If its last 3 digits have 0 then it is divisible by 8
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Solution:
(a) 572⇒ Divisible by 4 as its last two digits (72) are divisible by 4.
⇒ Not divisible by 8 as its last three digits(572) are not divisible by 8.
(b) 726352 ⇒Divisible by 4 as its last two digits(52) are divisible by 4.
⇒Divisible by 8 as its last three digits(352) are divisible by 8.
(c) 5500 ⇒ Divisible by 4 as its last two digits(00) are divisible by 4.
⇒ Not divisible by 8 as its last three digits(500) are not divisible by 8.
(d) 6000 ⇒Divisible by 4 as its last two digits are 0.
⇒Divisible by 8 as its last three digits are 0.
(e) 12159 ⇒ Not divisible by 4 and 8 as it is an odd number.
(f) 14560 ⇒Divisible by 4 as its last two digits(60) are divisible by 4.
⇒ Divisible by 8 as its last three digits(560) are divisible by 8.
(g) 21084 ⇒ Divisible by 4 as its last two digits(84) are divisible by 4.
⇒ Not divisible by 8 as its last three digits(084) are not divisible by 8.
(h) 31795072 ⇒ Divisible by 4 as its last two digits(72) are divisible by 4.
⇒Divisible by 8 as its last three digits(072) are divisible by 8.
(i) 1700 ⇒Divisible by 4 as its last two digits are 0.
⇒ Not divisible by 8 as its last three digits(700) are not divisible by 8.
(j) 2150 ⇒ Not divisible by 4 as its last two digits(50) are not divisible by 4.
⇒ Not divisible by 8 as its last three digits(150) are not divisible by 8
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Hope this will help you.....
A number will be divisible by 4 if the number formed by its tens and ones digit(Last two digits) is divisible by 4.
If its ones place is odd then it is not divisible by 4
If its last 2 digits have 0 then it is divisible by 4
.Divisibility by 8
A number will be divisible by 8 only when the number formed by hundreds tens and ones digit( last 3 digits) is divisible by 8.
If its ones place is odd then it is not divisible by 8.
If its last 3 digits have 0 then it is divisible by 8
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Solution:
(a) 572⇒ Divisible by 4 as its last two digits (72) are divisible by 4.
⇒ Not divisible by 8 as its last three digits(572) are not divisible by 8.
(b) 726352 ⇒Divisible by 4 as its last two digits(52) are divisible by 4.
⇒Divisible by 8 as its last three digits(352) are divisible by 8.
(c) 5500 ⇒ Divisible by 4 as its last two digits(00) are divisible by 4.
⇒ Not divisible by 8 as its last three digits(500) are not divisible by 8.
(d) 6000 ⇒Divisible by 4 as its last two digits are 0.
⇒Divisible by 8 as its last three digits are 0.
(e) 12159 ⇒ Not divisible by 4 and 8 as it is an odd number.
(f) 14560 ⇒Divisible by 4 as its last two digits(60) are divisible by 4.
⇒ Divisible by 8 as its last three digits(560) are divisible by 8.
(g) 21084 ⇒ Divisible by 4 as its last two digits(84) are divisible by 4.
⇒ Not divisible by 8 as its last three digits(084) are not divisible by 8.
(h) 31795072 ⇒ Divisible by 4 as its last two digits(72) are divisible by 4.
⇒Divisible by 8 as its last three digits(072) are divisible by 8.
(i) 1700 ⇒Divisible by 4 as its last two digits are 0.
⇒ Not divisible by 8 as its last three digits(700) are not divisible by 8.
(j) 2150 ⇒ Not divisible by 4 as its last two digits(50) are not divisible by 4.
⇒ Not divisible by 8 as its last three digits(150) are not divisible by 8
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Hope this will help you.....
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