1250-1300;Middle Englishamounten, amunten < Anglo-Frenchamo(u)nter, amunter,Old Frenchamonter literally, to go up, ascend, probably a-a-5 + monter (see mount1); E noun use of v. from early 18th cent.
Can be confused
amount, number (see usage note at the current entry)
The traditional distinction between amount and number is that amount is used with mass or uncountable nouns (the amount of paperwork; the amount of energy) and number with countable nouns (a number of songs; a number of days). Although objected to, the use of amount instead of number with countable nouns occurs in both speech and writing, especially when the noun can be considered as a unit or group (the amount of people present; the amount of weapons) or when it refers to money (the amount of dollars paid; the amount of pennies in the till).
mid-13c., "to go up, rise," from O.Fr. amonter, from a mont "upward," lit. "to the mountain," from L. ad- "to" + montem acc. sing. of "mountain." Meaning "to rise in number or quality (so as to reach)" is from c.1300. The noun is 1710, from the verb.