Strobogrammatic number Strobogrammatic number A strobogrammatic number is a number whose numeral is rotationally symmetric, so that it appears the same when rotated 180 degrees. In other words, the numeral looks the same right-side up and upside down (e.g., 69, 96, 1001). A strobogrammatic prime is a strobogrammatic number that is also a prime number, i.e., a number that is only divisible by one and itself (e.g., 11). It is a type of ambigram, words and numbers that retain their meaning when viewed from a different perspective, such as palindromes. When written using standard characters (ASCII), the numbers, 0, 1, 8 are
Course Setting Bomb Sight wires to tune out any sideways drift and thereby find the exact wind direction. The bearing plate is rotated to the compass heading and locked, thereby recording the wind direction for future reference. The pilot then turned 90 degrees to one side or the other, placing the wind directly off the side of the aircraft. The bomb aimer then rotated the milled head to the same 90 degrees. At this point the wind speed knob is adjusted, pushing the drift bar sideways until objects on the ground could be seen moving directly along the drift wires. The wind speed is