Ten

דברים ח ,ח: אֶרֶץ חִטָּה וּשְעֹרָּה וְגֶפֶן וּתְאֵנָּה וְרִ מוֹן אֶרֶץ-זֵית שֶמֶן וּדְבָּש:

This Pasuk, says the Baal HaTurim, contains ten words, which explains why we place all ten fingers on the bread when reciting the B'rachah of ha'Motzi. Furthermore, he explains, it corresponds to the ten Mitzvos that are performed with the bread, starting from its earliest stages: Not to plow with an ox and a donkey; Not to plant Kil'ayim; To leave Leket, Shikchah and Pe'ah; Not to muzzle an ox whilst it is threshing; To give Terumah, Ma'aser Rishon, Ma'aser Sheini and Chalah to the appropriate recipients.