上半部分

• ⺊(dot above; high position)ASSOCIATIVE
• 一(standard baseline; norm)ASSOCIATIVE

A dot mark sitting above a horizontal line represents the meaning 'above'.

• 丷(two diagonal strokes; division in half)ASSOCIATIVE
• 牛(cow; cattle)ASSOCIATIVE

Using a knife to split a cow in half equally shows the meaning of 半 (half).

• 咅(sound reading (radical/section))PHONETIC
• 阝(village; region)RADICAL

A section of land divided by distinct sounds becomes a region's administrative division.

• 八(divide; separate; eight)ASSOCIATIVE
• 刀(knife; blade; sword)RADICAL

Using a knife to chop something in half represents division or separation.