It looks like they've instead made a ring version of the CA-53W, which - in the staggeringly few times I see someone wearing a calculator watch - is usually the one they're wearing.
I still wear a DBC-610 as my daily driver, and I do use the calculator and countdown timer features quite often.
Actually, I think an abacus ring is a great idea or it could be multiple rings on the same finger where the main benefit is you could keep keep count of something. If you had three rows of small beads, you could theoretically keep track of up to a thousand things, all without a battery and with perfect accuracy. Additionally, you could keep track in a very low profile way if the beads were on the inside of the ring toward the palm of your hand and you manipulated them with your thumb. The beads would have to have a slight friction to them so they stay in place but are still easy to move. But in general I like the idea and it's at least as appealing as the op Casio watch ring.
It looks like they've instead made a ring version of the CA-53W, which - in the staggeringly few times I see someone wearing a calculator watch - is usually the one they're wearing.
I still wear a DBC-610 as my daily driver, and I do use the calculator and countdown timer features quite often.