THE NUMBERS THAT are used in counting (1, 2, 3, 4 . . . ) are called integers. Arithmetic is the study of integers with respect to what is known as the four fundamental operations of arithmetic: addition, subtraction, multiplication, and division. (Lewis Carroll's Mock Turtle, you may remember, called them Ambition, Distraction, Uglification, and Derision.) Arithmetic also includes the operations of raising a number to a higher power (multiplying it by itself a certain number of times), and of extracting a root (finding a number which, when multiplied by itself a certain number of times, will equal a given number). It goes without saying that you will never be able to learn algebra or any higher branch of mathematics without knowing your arithmetic well. But even if you never learn algebra, you will find that arithmetic is essential to almost every profession you can think of. A waitress has to add the items on a check, a farmer has to calculate the yield of his crops. Even a shoeshine boy must be able to make change correctly, and making change is pure arithmetic. It is as important in daily life as know how to tie your shoelaces. The puzzles in this section and the two that follow call for nothing more than the ability to do simple arithmetic; and to think clearly about what you are doing.
THE NUMBERS THAT are used in counting (1, 2, 3, 4 . . . ) are called integers. Arithmetic is the study of integers with respect to what is known as the four fundamental operations of arithmetic: addition, subtraction, multiplication, and division. (Lewis Carroll's Mock Turtle, you may remember, called them Ambition, Distraction, Uglification, and Derision.) Arithmetic also includes the operations of raising a number to a higher power (multiplying it by itself a certain number of times), and of extracting a root (finding a number which, when multiplied by itself a certain number of times, will equal a given number). It goes without saying that you will never be able to learn algebra or any higher branch of mathematics without knowing your arithmetic well. But even if you never learn algebra, you will find that arithmetic is essential to almost every profession you can think of. A waitress has to add the items on a check, a farmer has to calculate the yield of his crops. Even a shoeshine boy must be able to make change correctly, and making change is pure arithmetic. It is as important in daily life as know how to tie your shoelaces. The puzzles in this section and the two that follow call for nothing more than the ability to do simple arithmetic; and to think clearly about what you are doing. 
No comments