Or you could use the DS18B20 temperature sensor.
You need a single digital pin of the Arduino, one resistor of 4k7 and 10 of those sensors for less than 1 dollar per sensor. Search Ebay for "10pcs ds18b20".
The OneWire library is needed, an example for the DS18B20 is included, http://playground.arduino.cc/Learning/OneWire
The length of the cable is limited, I don't know at what distance the temperature sensors are.
It might not be your goal, but you won't get higher accuracy with analog sensors and a multiplexer and a analog input of the Arduino.