Nanci, what you're talking about is a kilojoule... (Calories aren't that logical - they're not metric.)

Lise, probably the back of the TimTam packet is talking in kilojoules too (food labels certainly are in kJ on things manufactured in NZ). There are about 10 of them in a "calorie" (which I think is actually a kilocalorie, but is never called that in the nutrition world..?), so each bicky probably has 30-or 40-something calories.

Wait! I've lied:

1 Calorie [nutritional] = 4.1868 kilojoules
1 kilojoule = 0.238845897 Calories [nutritional]

So:

390 kilojoules = 93.149899685 Calories [nutritional] (Thank you www.onlineconversion.com.)

But surely Arnotts can't be trying to tell you that the serving size is one lonely TimTam? More power to anyone who can eat those things one at a time.