Page 145 - NUMINO Challenge_D2
P. 145
Answe Problem solving
r
Key 1 If seven pancakes are divided equally among
4 The card that shows a picture is a card that was 12 people, the portion each person gets is 7 .
12
flipped an odd number of times. Therefore the
number on that card has an odd number of If one pancake is divided equally among 12 people,
factors. Since the number that has an odd
number of factors is a square number, then the portion each person gets is 1 .
there are 10 cards that have square numbers, 12
which are 1 1 1, 2 2 4, 3 3 9, 4 4 16,
5 5 25, 6 6 36, 7 7 49, 8 8 64, Therefore, since 7 1 1 , I am .
9 9 81, 10 10 100. Therefore, the number 12 12 2
of cards showing their numbers is 100 10 90.
3 Egyptian Fractions p.24~p.25 2 Find the proper divisors among the factors of
12. 1, 2, 3, 4, 6
Choose the factors that add up to 12.
2 4 6, 1 2 3 6
Example 13, 1 20, 1 246
13 20 12
1
246
12 12 12
111
632
1 1 23 6
12
Example 2 7, 1 21, 1
3 7 21 1236
12 12 12 12
2 1 1 6
3 , 7 , 21 , 7 1111
12 6 4 2
Type 3-1 Representing as a Fraction Unit p.26~p.27 1 1 1 or 1 1 11
2 3 6 2 4 6 12
1 14, 27
Type 3-2 Fibonacci's 'Greedy Procedure' p.28~p.29
2 Factors of 18: 1, 2, 3, 6, 9, 18 1 1 7 1 1
2 3 9 14 3 18 2 3
Therefore, the fraction is 14 .
18
7 2 Since 1 8 , 8 1 7 , and since
9 2 9 9 2 18
3 The three different unit fractions of :
1 7 1 7 1 1
3 18 2 , 18 3 18 .
7 14 2 3 9 8111
9 18 18 18 18 9 2 3 18
111 2 Since 1 7 , 7 1 8 , and since
962 2 18 18 2 18
1 8 1 , 8 1 1 .
3 18 2 18 3 9
17 1 1 1
18 2 3 9
NUMINO Challenge D2
r
Key 1 If seven pancakes are divided equally among
4 The card that shows a picture is a card that was 12 people, the portion each person gets is 7 .
12
flipped an odd number of times. Therefore the
number on that card has an odd number of If one pancake is divided equally among 12 people,
factors. Since the number that has an odd
number of factors is a square number, then the portion each person gets is 1 .
there are 10 cards that have square numbers, 12
which are 1 1 1, 2 2 4, 3 3 9, 4 4 16,
5 5 25, 6 6 36, 7 7 49, 8 8 64, Therefore, since 7 1 1 , I am .
9 9 81, 10 10 100. Therefore, the number 12 12 2
of cards showing their numbers is 100 10 90.
3 Egyptian Fractions p.24~p.25 2 Find the proper divisors among the factors of
12. 1, 2, 3, 4, 6
Choose the factors that add up to 12.
2 4 6, 1 2 3 6
Example 13, 1 20, 1 246
13 20 12
1
246
12 12 12
111
632
1 1 23 6
12
Example 2 7, 1 21, 1
3 7 21 1236
12 12 12 12
2 1 1 6
3 , 7 , 21 , 7 1111
12 6 4 2
Type 3-1 Representing as a Fraction Unit p.26~p.27 1 1 1 or 1 1 11
2 3 6 2 4 6 12
1 14, 27
Type 3-2 Fibonacci's 'Greedy Procedure' p.28~p.29
2 Factors of 18: 1, 2, 3, 6, 9, 18 1 1 7 1 1
2 3 9 14 3 18 2 3
Therefore, the fraction is 14 .
18
7 2 Since 1 8 , 8 1 7 , and since
9 2 9 9 2 18
3 The three different unit fractions of :
1 7 1 7 1 1
3 18 2 , 18 3 18 .
7 14 2 3 9 8111
9 18 18 18 18 9 2 3 18
111 2 Since 1 7 , 7 1 8 , and since
962 2 18 18 2 18
1 8 1 , 8 1 1 .
3 18 2 18 3 9
17 1 1 1
18 2 3 9
NUMINO Challenge D2
