If you’re taking a regular taxi, ask for taximeter. By law, the drivers must use the meter. As you can see in the picture, on the taximeter there are three digits before the dot. This makes some people think it shows the price of 385 JOD or 38.5 JOD but in fact, this is 3.85 JOD. Give no more than 3.85 JOD.
If they start complaining, you have two options: give 3.85 JOD to the driver and leave OR take a picture of the meter (and driver if possible) and tell them you will report this to the police.
Avoid giving the driver large bills, as they may not have change and could claim you gave them a smaller bill.