If one square takes 16.4 cm of wire, this means that to form 25 identical squares you need 25(16.4) cm of wire = 410 cm
To convert this to m you just need to divide it by 100 because there are 100 cm in one meter = 4.1 m
Therefore your final answer is: You need 4.1 m of wire to form 25 squares, each with a perimeter of 16.4 cm.