Page 146 - NUMINO Challenge_C2
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Creative Thinking p.30~p.31 4 The number of store points used to buy 8 bags
1 Since the number is divisible by 5, then the ones of chips is a multiple of 8, so it can be either
or .
digit is 5. To make the number divisible by 3, The number of store points used to buy 3
bottles of juice is a multiple of 3, so it can be
the sum of the digits must be a multiple of 3; either or .
The number of store points used to buy 12
therefore, in 5, the can either be 4 oranges is a multiple of 12, so it is also a
multiple of both 3 and 4, so it is .
or 7. Therefore, in 5, the numbers that can
is the store points for the oranges, for the
go in are 1 and 3, or 3 and 4. Therefore, bags of chips, and for the bottles of juice.
Therefore, 5,120 8 640 points are used to
the 3-digit numbers are 135, 315, 345, and 435. buy 1 bag of chips, 9,975 3 3,325 points are
used to buy 1 bottle of juice, and 3,840 12
2 The multiples of 18 are also multiples of 2 and 9. 320 points are used to buy 1 orange.
To make a multiple of 9, the sum of the digits
must be a multiple of 9; therefore, the three
number cards can be: (6, 3, 0), (6, 2, 1), (5, 4, 0),
(5, 3, 10), and (4, 3, 2). From the number cards
given above, the numbers that have 0, 2, 4, and
6 in the ones are:
(6, 3, 0) 630, 360, 306
(6, 2, 1) 612, 216, 162, 126
(5, 4, 0) 540, 504, 450
(4, 3, 2) 432, 342, 324, 234
Therefore, there are 3 4 3 4 14 numbers
that are multiples of 18.
3 The total number of store points is a multiple of
45; therefore, it is also a multiple of both 5 and
9. Since the digit in the ones place is 0, if the
sum of the digits is a multiple of 9, then it is also
a multiple of 45. Therefore, since 1 2 8 1
0 12, 6.
The total number of store points is 128,160.
Answer Key
1 Since the number is divisible by 5, then the ones of chips is a multiple of 8, so it can be either
or .
digit is 5. To make the number divisible by 3, The number of store points used to buy 3
bottles of juice is a multiple of 3, so it can be
the sum of the digits must be a multiple of 3; either or .
The number of store points used to buy 12
therefore, in 5, the can either be 4 oranges is a multiple of 12, so it is also a
multiple of both 3 and 4, so it is .
or 7. Therefore, in 5, the numbers that can
is the store points for the oranges, for the
go in are 1 and 3, or 3 and 4. Therefore, bags of chips, and for the bottles of juice.
Therefore, 5,120 8 640 points are used to
the 3-digit numbers are 135, 315, 345, and 435. buy 1 bag of chips, 9,975 3 3,325 points are
used to buy 1 bottle of juice, and 3,840 12
2 The multiples of 18 are also multiples of 2 and 9. 320 points are used to buy 1 orange.
To make a multiple of 9, the sum of the digits
must be a multiple of 9; therefore, the three
number cards can be: (6, 3, 0), (6, 2, 1), (5, 4, 0),
(5, 3, 10), and (4, 3, 2). From the number cards
given above, the numbers that have 0, 2, 4, and
6 in the ones are:
(6, 3, 0) 630, 360, 306
(6, 2, 1) 612, 216, 162, 126
(5, 4, 0) 540, 504, 450
(4, 3, 2) 432, 342, 324, 234
Therefore, there are 3 4 3 4 14 numbers
that are multiples of 18.
3 The total number of store points is a multiple of
45; therefore, it is also a multiple of both 5 and
9. Since the digit in the ones place is 0, if the
sum of the digits is a multiple of 9, then it is also
a multiple of 45. Therefore, since 1 2 8 1
0 12, 6.
The total number of store points is 128,160.
Answer Key
