An electronic device displays at least a portion of an electronic document with a predefined page layout at a first magnification level on a display; detects a first input indicating a first insertion point in the document, where the first insertion point is proximate to a first portion of text in the document; and in response to detecting the first input: selects a second magnification level different from the first magnification level, where the second magnification level is selected so as to display the first portion of text at a target text display size, and, while maintaining the predefined page layout of the document, displays, at the second magnification level, a portion of the document that includes the first portion of text.