Page 134 - NUMINO Challenge_D2
P. 134
Problem solving Key Points
1 If 3 is entered in the example below, the result of Calculate backwards
the calculation is 20. What is the first number to starting from 11 by
be entered to have 11 as the result of the changing the
calculation when using the same method as the operation signs as
example? shown below.
Example
3
8
2
3
49
20 3
11
2 If the two digits of a number are added as shown The 2-digit numbers
that have the result
in the example, the final result of the calculation of 2 after adding its
digits are 11 and 20.
will be a 1-digit number.
Example
48 12
48 12 3
Find all the 2-digit numbers that have the final
result of 2 after going through the two steps of
the method shown above.
131Communication
1 If 3 is entered in the example below, the result of Calculate backwards
the calculation is 20. What is the first number to starting from 11 by
be entered to have 11 as the result of the changing the
calculation when using the same method as the operation signs as
example? shown below.
Example
3
8
2
3
49
20 3
11
2 If the two digits of a number are added as shown The 2-digit numbers
that have the result
in the example, the final result of the calculation of 2 after adding its
digits are 11 and 20.
will be a 1-digit number.
Example
48 12
48 12 3
Find all the 2-digit numbers that have the final
result of 2 after going through the two steps of
the method shown above.
131Communication
