Earth: 土 (3)

土 is called つち・つちへん and commonly points to soil, ground, or things built on land. 墳 is a burial mound, 坑 a pit, and 塀 a wall; 塊 is a lump of earth, while other meanings in the group are less literal.

坪 has 8 strokes and 墾 has 16. When 土 is on the left, write it narrow; in 坪 it sits below, so keep the two 土 shapes distinct.