1 This generally includes replacing a few parts like hoses, sensors, or either the compressor or condenser. 2  CostHelper readers report paying $171-$727 for minor air conditioning repairs, at an average cost of $488. 3  Extensive auto air conditioning repairs can cost $1,000-$4,000 or more, depending on make and model.
Their numerical system is similar to that of the Romans, but instead of Xâs and Iâs they use dots, bars and shells. Each dot has the value of one, each bar the value of five, and each shell the value of zero. This brings us to the main mathematical contribution of the Mayans, the concept of zero.
But by far their most sophisticated use of mathematics was in astronomy. Much of knowledge of Aztec astronomy has been lost, but the there's a good synthesis of the surviving information in the book Skywatchers by Anthony Aveni. Following the Maya, the Aztecs had good calculations of the movements of many of the classical planets. For example, they calculated the cycle of Venus at 584 days (the time it takes Venus to overtake earth in its orbit.)