While viewing the page, tap the Menu icon (at the upper-right corner of the screen), then tap Find in page.
Type the text you’re looking for in the find bar at the top of the screen. Matches are highlighted on the page (the current match in orange and the remaining matches in yellow).
The find bar displays the total number of matches. Tap the up and down arrows (to the right of the find bar) to go to each match.
Found matches are also indicated in the scroll column along the right side of the screen. Tap any of the highlights to jump directly to that match.