2 EXPLANATIONS OF THE CHARACTERS USED IN THE FOLLOWING TABLES AND CALCULATIONS. = Equal to, as, 12 inches 1 foot, or 8x8=16×4. + Plus, or more, signifies addition; as, 4+6+5=15. Minus, or less, signifies subtraction; as, 15-5=10. X Multiplied by, or into, signifies multiplication; as, 8×9=72. Divided by, signifies division; as, 72-98. : Is to :: so is : to } Proportion; as, 2:4::8:16; that is, as 2 is to 4 so is 8 to 16. Prefixed to any number signifies that the square root of that number is required; as, 16=4; that is, 4x4 = 16. Signifies that the cube root of that number is required; as, 3/644; that is, 4x4x4 64. 2 added to a number signifies that that number is to be squared; thus, 42, means that 4 is to be multiplied by 4. added to a number signifies that that number is to be cubed; thus, 43,is 4X4X4 64. The power, or number of times a number is to be multiplied by itself is shown by the number added; as, 2 3 4 5, &c. The bar signifies that the numbers are to be taken together; as, 8-2+6=12, or 3×5+3=24. Decimal point, signifies when prefixed to a number, that that number has a unit (1) for its denominator; as, .1 is, .155 is 155, &c. Signifies difference, and is placed between two quantities when it is not evident which of them is the greater. • Degrees, minutes, "seconds, ''' thirds. < Signifies angle. a-1, a-2, a- 3, &c., denote inverse powers of a, and are equal to 1 1 al' " 3' a 7 Is put between two quantities to express that the former is greater than the latter; as, a7 b, reads a greater than 6. L Signifies the reverse; as, a Lb, reads a less than b. () Parentheses are used to show that all the figures within them are to be operated upon as if they were only one; thus, (3+2)x5=25. p is used to express the ratio of the circumference of a circle to its diameter 3.1415926, &c. A A'A" A"" signifies A, A prime, A second, A third, &c. axd, a.d, or ad, signifies that a is to be multiplied by d. Note. The degrees of temperature used in this work are those of Fahrenheit. |