Simplify the following text for a Grade 6 native English-speaking person.
Original: Ni-hachi ( ä å `` , two-eight ) soba , consists of two parts of wheat and eight of buckwheat ; Juuwari ( å å , 100 % ) soba , the finest ( and usually most expensive ) variety , consists entirely of buckwheat .
Simplified: Ni-hachi ( two-eight ) soba , consists of two parts of wheat and eight of buckwheat .