This equation is incomplete: 1 2 3 4 5 6 7 8 9 = 100

One way to make it accurate is by adding seven plus and minus signs, like so.

1 + 2 + 3 – 4 + 5 + 6 + 78 + 9 = 100

How can you do it using only 3 plus or minus signs?

Six glasses are all in a row in front of you, the first three are full of grape juice and the last three are empty. Moving only one glass, how can you make all six alternate between full and empty?

What do these dates have in common?

15 February 1984
2 July 1983
16 December 1983

How far can a dog run into the forest?

What two-digit number is the square of one number and the cube of another?