Filed under radical 十 (shí, #24) by convention. 十 is not a separate component in 干, so no strokes are highlighted.
Pictograph of a forked weapon used both for offense and as a shield. As an indexing radical it organizes a small handful of characters such as 平 (level), 年 (year), 幸 (fortunate), 幹 (trunk/to do). Productivity is modest; the radical is more important for lookup than for meaning hints.