Page 142 - NUMINO Challenge_B1
P. 142
Type 1-2 Happy Number p.12~p.13 3 and 6. The remaining digits are 1, 4, and 5. 5
is the only digit that can be placed in between 1
1 Because 7 is a definite answer, the six remaining and 3. Write 4 in the last blank box.
digits must add up to 23. If you add up all other
possible digits, 1 2 3 4 5 6 8 9 38. 741538629
To have a sum of 23, you must remove two or 9 2 6 8 3 5 1 4 7
digits that add up to 15. Therefore, 9 and 6
must be removed. Creative Thinking p.14~p.15
1, 2, 3, 4, 5, 7, 8
2 8 is the greatest digit out of the digits obtained 1 Write the numbers 1 to 6 around the circle in
above.
alphabetic order. 1 6 7 and 3 4 7, so
3 The remaining digits are 1, 2, 3, 4, and 5. The these sums that face each other are equal, but
only digit that is divisible by 3 is 3. Therefore, the sum of two numbers on the left side is 6
put 3 in the 6th and 1 in the last . more than the sum of two numbers on the right
side. Switch 2 and 5 to complete the order of
4 The remaining digits are 2, 4, and 5. 7 is the 4th numbers.
digit, so the only possible solution is to use the
equation 7 5 2 or 7 2 5 to find the 3rd and 1 1 1
5th digit. The greatest 7-digit number that 62 62 65
meets all the conditions is 8457231.
53 5 3 23
4 4 4
Answers will vary.
Problem solving 2 All the arrows start off from , so it must be 1,
1 The last digit is 7, the 1st digit is 5, and the digit the smallest number. Looking at the direction of
the arrows, , , and are greater than .
in the center is 2. According to the condition , Therefore, is 2, the second smallest number.
the 6th digit is equal to 3. The remaining digits Fill in the remaining 's according to the rule.
are 1, 4, and 6. According to the condition ,
the 2nd and 3rd digits must be 1 and 4. 1 41 3
Therefore, the 5th digit must be 6. The smallest
7-digit number that meets all the conditions is 2 52 5
5142637.
34
2 The sum of digits from 1 to 9 is 45. The sum of
the digits between 7 and 9 is 29, which is
45 7 9. Place 7 and 9 in the first and last
boxes. The remaining digits, 1, 2, 3, 4, 5, and 8
add up to 23. Since the sum of the digits
between 6 and 7 is 21, 2 comes next to 9 on the
end, and 6 comes next to 2. The remaining
digits are 1, 3, 4, 5, and 8. According to the rule,
8 is the only digit that can be placed in between
Answer Key
is the only digit that can be placed in between 1
1 Because 7 is a definite answer, the six remaining and 3. Write 4 in the last blank box.
digits must add up to 23. If you add up all other
possible digits, 1 2 3 4 5 6 8 9 38. 741538629
To have a sum of 23, you must remove two or 9 2 6 8 3 5 1 4 7
digits that add up to 15. Therefore, 9 and 6
must be removed. Creative Thinking p.14~p.15
1, 2, 3, 4, 5, 7, 8
2 8 is the greatest digit out of the digits obtained 1 Write the numbers 1 to 6 around the circle in
above.
alphabetic order. 1 6 7 and 3 4 7, so
3 The remaining digits are 1, 2, 3, 4, and 5. The these sums that face each other are equal, but
only digit that is divisible by 3 is 3. Therefore, the sum of two numbers on the left side is 6
put 3 in the 6th and 1 in the last . more than the sum of two numbers on the right
side. Switch 2 and 5 to complete the order of
4 The remaining digits are 2, 4, and 5. 7 is the 4th numbers.
digit, so the only possible solution is to use the
equation 7 5 2 or 7 2 5 to find the 3rd and 1 1 1
5th digit. The greatest 7-digit number that 62 62 65
meets all the conditions is 8457231.
53 5 3 23
4 4 4
Answers will vary.
Problem solving 2 All the arrows start off from , so it must be 1,
1 The last digit is 7, the 1st digit is 5, and the digit the smallest number. Looking at the direction of
the arrows, , , and are greater than .
in the center is 2. According to the condition , Therefore, is 2, the second smallest number.
the 6th digit is equal to 3. The remaining digits Fill in the remaining 's according to the rule.
are 1, 4, and 6. According to the condition ,
the 2nd and 3rd digits must be 1 and 4. 1 41 3
Therefore, the 5th digit must be 6. The smallest
7-digit number that meets all the conditions is 2 52 5
5142637.
34
2 The sum of digits from 1 to 9 is 45. The sum of
the digits between 7 and 9 is 29, which is
45 7 9. Place 7 and 9 in the first and last
boxes. The remaining digits, 1, 2, 3, 4, 5, and 8
add up to 23. Since the sum of the digits
between 6 and 7 is 21, 2 comes next to 9 on the
end, and 6 comes next to 2. The remaining
digits are 1, 3, 4, 5, and 8. According to the rule,
8 is the only digit that can be placed in between
Answer Key
