Mat 10:30 But even the hairs of your head are all numbered.
Mat 10:31 Fear not therefore, you are of more value than many sparrows.

"Hair" is thrix, which is both the hair of humans and animals.

"Numbered" is arithmeo, (look familiar?) which means "to count," and "to number," but for the tax collector it also means "to count out," "to pay," and "to account."

If you notice, the previous verse is about the price and value of things. A more accurately translation could be "But even the head of your head are accounted for" of even "paid for."

"Are of more value" is from diaphero, which means "to bear or carry though a place," "to carry in different ways," "to test," "to prove," "to differ," "to excel," "to surpass," and "to quarrel."

Here the meaning seems to be "to surpass," but there are other possibilities.

"Than many" is polus, which means just "many," "much," or "large." There is no "than" in the verse, but Greek really doesn't have a word that works like "than."

I would translated this last verse as "Fear not therefore, you surpass many sparrows." With unspoken idea being that we surpass both the value of sparrows in God's eyes and in the amount of attention we get from God.