Fractions – Math

[Ref http://www.math.com/tables/general/numnotation.htm] Fractions Digits to the right of the decimal point represent the fractional part of the decimal number. Each place value has a value that is one tenth the value to the immediate left of it. Examples: 0.123 = 123/1000 (said – point 1 2 3, or 123 thousandths, or two hundred thirty four thousandths) […]

Math – formula

[Ref http://www.math.com/tables/geometry/areas.htm] Area [面積] square = a 2 rectangle = ab parallelogram 平行四邊形 = bh trapezoid 梯形 = h(b1 + b2)/2 circle = pi r 2 ellipse = pi r1 r2 triangle = bh/2 equilateral triangle = [(√3)/4]( a 2 )   Perimeter [圓周] square = 4a rectangle = 2(a+b) triangle = a + b + c circle = 2pi r    Volume [體積] cube = a 3 rectangular prism = = a b c cylinder =  pi r 2 h pyramid = (1/3) b h cone = […]

Scale

[Ref FAA-H-8083-18 Flight Navigator Handbook] The ratio between any given unit of length on a chart and the true distance it represents on the earth is the scale of the chart. Charts are made to various scales for different purposes. If a chart is to show the whole world and yet not be too large, […]

Division

[Ref. WIKI – https://en.wikipedia.org/wiki/Division_(mathematics)] dividend over the divisor “a divided by b”, “a by b” or “a over b”. dividend is divided by the divisor to get a quotient. Example: 20 ÷ 5 = 4 20 is the dividend, 5 is the divisor, 4 is the quotient. In some cases, the divisor may not be contained fully […]