The very important flight number likely relates to the airline's history. Delta's very first international destination was London in 1978 . (Although, back then, the flight operated from Atlanta.) ...

In the exercise below, you must “crack the code” of the Babylonian number system. On the right, under the heading Column B, you’ll see an assortment of familiar Arabic numbers.

Brain teaser: Can you crack the code and find the missing number in the triangle? A popular online math puzzle involves finding a missing number in triangles by using a simple addition rule.