计算机专业英语（第二版） -孙建忠 Chapter3.pptVIP

Computer English Chapter 3 Binary System and Boolean Algebra 数学公式的读法(Pronunciation of mathematical expressions) 3 实数(Real numbers) x+1 x plus one x-1 x minus one x±1 x plus or minus one xy xy / x multiplied by y (x-y)(x+y) x minus y, x plus y x over y = the equals sign x=5 x equals 5 / x is equal to 5 x≠5 x (is) not equal to 5 x≡y x is equivalent to (or identical with) y 3 实数(Real numbers) xy x is greater than y x≥y x is greater than or equal to y x y x is less than y x?y x is less than or equal to y 0x1 zero is less than x is less than 1 0?x?1 zero is less than or equal to x is less than or equal to 1 |x| mod x / modulus x x2 x squared / x (raised) to the power 2 x3 x cubed x4 x to the fourth / x to the power four xn x to the nth / x to the power n x-n x to the (power) minus n 数学公式的读法(Pronunciation of mathematical expressions) * * 在线教务辅导网： 教材其余课件及动画素材请查阅在线教务辅导网 QQ:349134187 或者直接输入下面地址： Key points:  useful terms and definitions of Binary system and Boolean AlgebraDifficult points:  Conversion of the Binary Systems and Boolean Algebra Requirements: Concepts of Number System and their conversion 2. Boolean Algebra 3. Moore’s Law 4. 科技英语中数学公式的读法 New Words Expressions: decimal system 十进制 abaci n. 算盘 verbal representation 口头表达式 radix n. 根, 基数 quinary system 五进制 duodecimal system 十二进制 stop at 停在 lie in 在于 in fact 事实上 in order to 为了 Roman-number n. 罗马数字 pencil-and-paper 纸和笔的 regardless of a.不管, 不顾 contraction n. 收缩，缩写式，紧缩 gross n. 罗，为一计数单位，1罗=12打 positional notation n. 位置记数法 3.1 The Decimal System Our present system of numbers has 10 separate symbols 0, 1, 2, 3,…, 9, wich are called Arabic numerals. We would be forced to stop at 9 or to invent more symbols if it were not for the use of positional notation. An example of earlier types of notation can be found in Roman numeral, which are essentially additive: III=I+I+I, XXV=X+X+V. New symbols (X, C, M, etc.) were used as the numbers inc