Ares to Arpent (Mauritius): the quick answer
1 a = 0.0236911 arpent-mu
1 are equals 0.0236911 arpent (Mauritius)
To convert ares to arpent (Mauritius), multiply the value by 0.0236911. To go the other way, multiply arpent (Mauritius) by 42.21 to get ares.