When we moved here, I saved myself some embarrassment in the grocery check-out thanks to my daughter. We had visited her in Italy while she was in college, and she taught us that you must weigh your own produce before you pay for it. Our first day here we noticed the scale with the numbers on it and I knew exactly what to do.
First you select your items, put them in a bag, note the number on the bin and put it on the scale. Press the corresponding number and a little sticky price tag comes out, and you put it on the bag. Since sometimes I forget to take bag a little plastic bag to reuse (otherwise they accumulate too quickly), and I buy only one item (one onion, one pepper), I just stick the tag right on to the food. I tend to buy onions one at a time, and the trick is to keep the tag on the outside without it sticking to something else in the basket.
You can see here that one red pepper costs the same as two apples.