But anyway, to help my students remember this one we say it funny and pronounce it the way it looks, like "sug-ar." Or I make a rhyme like "I drive my car to get su-gar." Or I would say something like, "I need A cup of sugAr." And I would write it like that on the board so they would see the big ol' capital "A." Thus, I have just demonstrated four different ways for them to remember the "A" in "sugar."
No, they will not remember all four of them. They probably won't even remember two of them. But almost always, they will remember one of them; the one that made the most sense to them whether they are verbal, visual, or kinesthetic, and that is enough to make them better spellers, better students, better thinkers, and better sign-makers if they ever mass produce produce.