Top is a 5-stroke contraction of standalone 尚 (8 strokes), the lower 口 dropped - the same shortcut as in 党. 尚 supplies the sound (shàng → cháng, regular zh-/ch- alternation). The three short top strokes form the ⺌ silhouette, which is why 尝 indexes under Kangxi #42 小 (xiǎo) by tradition.
Bottom 云 - a simplification of traditional 嘗's lower stack (旨 'delicious' over 甘 'sweet'). The original picture was 'tasting to assess flavor.' The reform replaced the inner taste-graphics with the simpler 云 (cloud), which is now a graphic placeholder rather than a meaning-carrier - a pure visual substitute.
Filed under radical 小 (xiǎo, #42) by convention. 小 is not a separate component in 尝, so no strokes are highlighted.
