Page 142 - NUMINO Challenge_C1
P. 142
Problem solving 4 The amount of money that the farmer will
1 The six digits in the first half of the answer is receive can be expressed as shown below.
1 day : 1 10 10 dollars
864327 1 864326. The six digits in the second 2 days : 2 2 10 40 dollars
half is 999999 864326 135673. 3 days : 3 3 10 90 dollars
4 days : 4 4 10 160 dollars
864326135673 Therefore, if the farmer works for 15 days, he
will receive 15 15 10 2250 dollars.
2 The number of spectators attending the stadium
2 Shape Numbers p.16~p.17
increased according to a pattern. The first and
last numbers are 6 and 3. The number of 9's in Example 2436 1765
between is 1 less than the number of 9's in the 4201,
number multiplied. Therefore, the number of
people who came to watch the finals was
6999993.
Creative Thinking p.14~p.15
Example 16, 8 ,4 17, 11, 28
16, 8, 4,
1 Split 2025 into 20 and 25. 20 25 45 and
Type 2-1 Mayan Numerals p.18~p.19
45 45 2025. So 2025 is a Kaprekar number.
Split 81 into 8 and 1. 8 1 9 and 9 9 81. 1 is 1 and is 5. Therefore, is 3 and
is 17.
So 81 is a Kaprekar number.
Split 3969 into 36 and 69. 36 69 109 and 2 77 60 17, so at the top represents 60
109 109 11664. So 3969 is not a Kaprekar and at the bottom represents 17.
number.
Therefore, is in the 20's place and is
Split 3123 into 31 and 23. 31 23 54 and in the 1's place.
54 54 2916. So 3123 is not a Kaprekar
number. 3 20 2 40
40 14 54
Split 9801 into 98 and 01. 98 01 99 and 1 14 14
99 99 9801. So 9801 is a Kaprekar number.
20 8 160 160 9 169
2 The last digits in the numbers multiplied (0, 1, 199
12, 123, 1234...) increase by one number. The 4 54 169 223 20 11 1 3. This is expressed
digits of the number multiplied is (the number as in Mayan numerals.
added) 1. Therefore, is 123. The number of
1's in the answer is equal to the number added.
Therefore, is eight 1's, 11111111.
3 The last two numbers are from the product of 9
and 5, which is 45. The numbers 5 and 4 are
from the product of 6 (the number greater than
5 by 1) and 9. There are five 5's and 4's.
999999 555555 555554444445
Answer Key
1 The six digits in the first half of the answer is receive can be expressed as shown below.
1 day : 1 10 10 dollars
864327 1 864326. The six digits in the second 2 days : 2 2 10 40 dollars
half is 999999 864326 135673. 3 days : 3 3 10 90 dollars
4 days : 4 4 10 160 dollars
864326135673 Therefore, if the farmer works for 15 days, he
will receive 15 15 10 2250 dollars.
2 The number of spectators attending the stadium
2 Shape Numbers p.16~p.17
increased according to a pattern. The first and
last numbers are 6 and 3. The number of 9's in Example 2436 1765
between is 1 less than the number of 9's in the 4201,
number multiplied. Therefore, the number of
people who came to watch the finals was
6999993.
Creative Thinking p.14~p.15
Example 16, 8 ,4 17, 11, 28
16, 8, 4,
1 Split 2025 into 20 and 25. 20 25 45 and
Type 2-1 Mayan Numerals p.18~p.19
45 45 2025. So 2025 is a Kaprekar number.
Split 81 into 8 and 1. 8 1 9 and 9 9 81. 1 is 1 and is 5. Therefore, is 3 and
is 17.
So 81 is a Kaprekar number.
Split 3969 into 36 and 69. 36 69 109 and 2 77 60 17, so at the top represents 60
109 109 11664. So 3969 is not a Kaprekar and at the bottom represents 17.
number.
Therefore, is in the 20's place and is
Split 3123 into 31 and 23. 31 23 54 and in the 1's place.
54 54 2916. So 3123 is not a Kaprekar
number. 3 20 2 40
40 14 54
Split 9801 into 98 and 01. 98 01 99 and 1 14 14
99 99 9801. So 9801 is a Kaprekar number.
20 8 160 160 9 169
2 The last digits in the numbers multiplied (0, 1, 199
12, 123, 1234...) increase by one number. The 4 54 169 223 20 11 1 3. This is expressed
digits of the number multiplied is (the number as in Mayan numerals.
added) 1. Therefore, is 123. The number of
1's in the answer is equal to the number added.
Therefore, is eight 1's, 11111111.
3 The last two numbers are from the product of 9
and 5, which is 45. The numbers 5 and 4 are
from the product of 6 (the number greater than
5 by 1) and 9. There are five 5's and 4's.
999999 555555 555554444445
Answer Key
