Positive and Negative Numbers (Signed Numbers) Positive numbers are numbers that are greater than zero. Negative numbers are numbers less than zero. [Figure 1-8] Signed numbers are also called integers. Addition of Positive and Negative Numbers The sum (addition) of two positive numbers is positive. The sum (addition) of two negative numbers is negative. The sum of a positive and a negative num..

Percentage Percentage means “parts out of one hundred.” The percentage sign is “%”. Ninety percent is expressed as 90% (= 90 parts out of 100). The decimal 0.90 equals 90⁄100, or 90 out of 100, or 90%. Expressing a Decimal Number as a Percentage To express a decimal number in percent, move the decimal point two places to the right (adding zeros if necessary) and then affix the percent..

Ratio A ratio is the comparison of two numbers or quantities. A ratio may be expressed in three ways: as a fraction, with a colon, or with the word “to.” For example, a gear ratio of 5:7 can be expressed as any of the following: 5⁄7 or 5:7 or 5 to 7 Aviation Applications Ratios have widespread application in the field of aviation. For example: Compression ratio on a reciprocating engine i..

Division of Decimal Numbers Division of decimal numbers is performed the same way as whole numbers, unless the divisor is a decimal. When the divisor is a decimal, it must be changed to a whole number before dividing. To do this, move the decimal in the divisor to the right until there are no decimal places. At the same time, move the decimal point in the dividend to the right the same number o..

The Decimal Number System The Origin and Definition The number system that we use every day is called the decimal system. The prefix in the word decimal is a Latin root for the word “ten.” The decimal system probably had its origin in the fact that we have ten fingers (or digits). The decimal system has ten digits: 0, 1, 2, 3, 4, 5, 6, 7, 8, and 9. It is a base 10 system and has been in use..

Reducing Fractions A fraction needs to be reduced when it is not in “lowest terms.” Lowest terms means that the numerator and denominator do not have any factors in common. That is, they cannot be divided by the same number (or factor). To reduce a fraction, determine what the common factor(s) are and divide these out of the numerator and denominator. For example when both the numerator and..

Subtraction of Fractions In order to subtract fractions, they must have a common denominator. If the fractions do not have the same denominator, then one or all of the denominators must be changed so that every fraction has a common denominator. Example: The tolerance for rigging the aileron droop of an airplane is 7⁄8 inch ± 1⁄5 inch. What is the minimum droop to which the aileron can be..

Multiplication of Whole Numbers Multiplication is the process of repeated addition. For example, 4 × 3 is the same as 4 + 4 + 4. The result is called the product. Example: How many hydraulic system filters are in the supply room if there are 35 cartons and each carton contains 18 filters? Therefore, there are 630 filters in the supply room. Division of Whole Numbers Division is the process of..

A&P License 교재 중 FAA 에서 발행하는 General Textbook 입니다. 오늘부터 원본으로 올려보도록 하겠습니다. 기초적인 부분은 원본만 올리도록 하고 추가 설명이 필요한 부분만 따로 첨삭형태로 강의 진행하도록 하겠습니다. Mathematics in Aviation Maintenance Mathematics is woven into many areas of everyday life. Performing mathemat..