Arithmetic branch of that deals with properties of the (and whole) numbers and fractions basic operations applied numbers. As a matter of , as a noun sense, the word quite . early grades, numbers object of study, as . The sticks around later it paradoxically becomes I. The latter of letters as place holders for generic or unknown numbers.
One for the common of the word arithmetic stems from that, besides learning numbers to them, students shapes of measurements, takes somewhat the of arithmetic. However, the common of "Mental Math" of basic calculations in one's head recourse to paper, pencil, or devices. The misnaming of is entrenched in education literature. The titles Children's , Doing and Children's Mathematical Development (the is so-so, the second , the third is excellent) characteristic field, 's Arithmetic and Young Children Reinvent Arithmetic(two classics) .