39846

NRICH -4 DIGIT TARGETS METHOD AND SOLUTION
BY ROSALYN ACEVEDO
METHOD
First of all I started off by writing out all the numbers that I could use for this problem such as:
0 1 2 3 4 5 6 7 8 9
0 1 2 3 4 5 6 7 8 9
So I could cross off the numbers I had used as I go so I don’t use numbers more than 2 times.
Afterwards I wrote the first number that I would use for each column such as:
The first number of the largest odd number that I would use then the first number that I would use for the largest even number then the first number I would use for the largest multiple of 3 then the first number I would use for the smallest multiple of 5 then the first number I would use for the number closest to 5000.
Next I would write the second number for all the columns just like I did for the first. Then I would write the third number for all the columns and then the fourth.
After I had done that I checked my work so I checked that the column that is the largest multiple of 3
and also the smallest multiple of 5 column and the largest odd number column and the largest even number column just to make sure my solution worked.
The solution that I came up with for this problem was
Largest odd number: 9973
Largest even number: 8864
Largest multiple of 3: 7623
Smallest multiple of 5: 1005
Number closest to 5000: 5142
By Rosalyn Acevedo