Movement cost totals with fractions

[Blackcloud6]

PG Math:

A tank unit moves from clear hex to clear/road hex and then proceeds to move one hex along the road.  What is it's total movement points used so far? 

Clear movement is 1.5, road is 2/3 so the math is

3/2 +2/3= 2 1/6  

But there are no sixths in PG movement so do I round up to the nearest third and say the vehicle moved 2 1/3?