Puzzles to test mathematical skills. Set by Anita Straker.
Age 8-11
Happy New Year
The digits of the year 2003 add up to 5.
In how many other years since 1AD has this happened?
Age 11-14
Remarkable numbers
The number 321654 is a six-digit remarkable number.
32 (the first two digits) is divisible by 2; 321 (the first three digits) is divisible by 3; 3216 (the first four digits) is divisible by 4; and so on until finally... all six digits make a number divisible by 6.
Arrange the digits 1 to 9 to make a nine-digit remarkable number.
BRAINTEASER SOLUTIONS
Happy New Year
The digits of the year have added up to 5 a total of 36 times since 1AD. The years are: 5, 14 ,23, 32, 41, 50, 104, 113, 122, 131, 140, 203, 212, 221, 230, 302, 311, 320, 401, 410, 500, 1004, 1013, 1112, 1031, 1040, 1103, 1112, 1121, 1130, 1202, 1211, 1220, 1301, 1310, 1400.
Remarkable numbers
381, 654, 729.