Same in Canada. Unit prices are useful for comparisons, but it's hard to avoid the big, colorful "ON SALE" tags.

Some stores in the US have that, some don’t, and it’s always a lot smaller than the total price when they do.

I've come to really enjoy grocery shopping, planning a week worth of meals, being adaptive when good deals come up, trying new things, working to minimize waste. Eating a healthy diet.

One of the things I like about grocery shopping is practicing mental math, and I calculate price per quantity mentally when choosing between different brands/sizes. It's good mental exercise, and the ability to do that sort of division mentally occasionally is helpful in other contexts.

What do you mean by "it's smaller than the total"? Do they literally write the wrong price or do they choose any unit they happen to think makes for a good sounding price per unit?

In most of Europe (probably all the EU countries at least, unified regulations yay) shops need to put the price per 1kg/100g/1L/100mL on the tags, depending on which is most appropriate for the product.

The physical printing is smaller.

Often much smaller. A few stores like Costco actually print it large enough that you don't have to get up close and squint at each price tag to see the unit price. Usually you can't just scan the shelf and comparison shop on unit price.

A lot of them that do mix units between products of the same class (one measured as volume per unit, and another as mass per unit), making it difficult to do a direct comparison.