I tried doing this by creating a custom “fake cloze” note type with three fields, Whole Sentence, Partial Sentence, and Cloze. (I cloned the Basic note type, then renamed the Front and Back fields of the clone, and added another field.) Then on the card templates, I put
{{Partial Sentence}}
{{type:Cloze}}
on the front and
{{Whole Sentence}}
{{type:Cloze}}
on the back.
Instead of using the Cloze toolbar items or shortcuts, you would type underscores for the cloze in the Partial Sentence field. So in your example, Whole Sentence would have “1 + 1 = 2”, Partial Sentence would have “1 + 1 = __”, and Cloze would have “2”.
Seems to work reasonably well for what you are asking. (You probably need to style and arrange fields to your liking.)
Since this is a fake cloze note type, it would take more work to have more than one cloze in a note, you would have to add more fields.
Another thing to consider is that from the Browser, you can also just hit Preview and then browse through the list using the arrow keys and look at the card previews instead of the “ugly code” in the background.
