The '+' operation between the 2 numbers here takes The number of loops in these numbers and adds them together. So 7 + 5 = 0 as (7 => has 0 loops and so does 5) 6 + 8 = 3 as (6 => has 1 loop and 8 => has 2 loops) In that sense 4 + 5 = 1 is the answer.
7+5=0, 6+8=3, 9+9=2, 9+1-1, 8+7=2, 4+5=2
Arrange all the digits 0, 1, 2, 3, 4, 5, 6, 7, 8, and 9 to give four different square numbers. (You make a square number when you multiply something by itself, so 49 is square because it is 7 times 7)
The digits 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 can be arranged into an addition sum to add up to almost any total, except that nobody has yet found a way to add up to 1984. However 9 digits can equal 1984 by an addition sum. Which digit is omitted?
