Meaning of 増える in this sentence?

Question

In the following sentence: > 魚は三匹に増えていた。 I don't know whether to interpret に as **to** or **by**. So if I start with one fish then: > The number of fish increased **to** three (there are now three fish), or > The number of fish increased **by** three (there are now four fish) Which is the correct translation and how would I modify the sentence to make it have the other meaning? Thanks.

Answer 1

NI would be "to" here. There were previously 2 fish, there are now 3.

DE would be "by," if I'm not mistaken.