Explanation of the Characters used in this Book. Equal to, as 12d.=1s. signifies that 12 pence are equal to 1 shilling. + More, the sign of Addition, as 5+7=12, signifies that 5 and 7 added together, are equal to 12. Minus, or less, the sign of Subtraction, as 6-2=4, signifies that 2 subtracted from 6 leaves 4. × Multiply, or with, the sign of Multiplication; as 4X3=12, signifies that 4 multiplied by 3, is equal to 12. : The sign of Division; as 8÷2=4, signifies that 8 divided by 2, is equal to 4; or thus, &=4, each of which signify the same thing. : Four points set in the middle of four numbers, denote them to be proportional to one another, by the rule of three; as 2: 4 :: 8:16; that is, as 2 to 4, so is 8 to 16. Prefixed to any number, supposes that the square root of that number is required. Prefixed to any number, supposes the cube root of that number is required. A dot, or inverted period, placed at the left hand of any figure or figures, (thus, 3-0-0) denotes that they are cancelled by other figures of the same denomination. |