I assume this is one of those "put operators in the right places to make this true" questions. Here's one solution:
9 ÷ 3 - 2 × 1 = 3 - 2 × 1 = 1 × 1 = 1
Really, most of these problems can be tackled by experimentation - you kind of have to develop a "feel" for these numbers and operations, and with enough experience, these kinds of things will just start coming naturally to you.