of business men is that these boys and girls be able to copy numbers correctly, to write them from dictation, to add, subtract, multiply, and divide whole numbers accurately; that they be able to multiply and divide numbers quickly by moving the decimal point; that they be able to use all the short methods of computing with numbers; that they be careful to check every addition and subtraction on a sales slip, a bill, a balance sheet, or a stock card. Three Cautions for the Pupil. The correct answer always is worth more than the rapid answer. While the business man prefers that his employee be quick at numbers, he insists that he be accurate. In the business world the only passing mark in arithmetic is 100%. Therefore, remember always, in all grades: (a) Write all figures neatly and clearly, the horizontal lines level and the columns straight. (b) Perform all operations by the shortest method you know. (c) Check every answer before you lay down your pencil. Notation and Numeration. The symbols, 1, 2, 3, 4, 5, 6, 7, 8, 9, 0, used in writing numbers, are Arabic numerals. In the number 946, what does 6 represent? What does 4 represent? What does 9 represent? The orders of numbers, reading from right to left, are: units, tens, hundreds, thousands, ten thousands, etc. The figures of a number are set off by commas, beginning at the right, into groups of three. The last group, that at the left, will consist of one, two, or three figures. These groups are called periods. The first six periods, reading from right to left, are: units, thousands, millions, billions, trillions, and quadrillions. Roman Numerals. What is the difference between Arabic and Roman numerals? 1. Read: V VI I II III IV IX XXX Add the values of the letters when a letter is followed by one or more letters of the same or less value. Subtract the values of the letters when a letter is followed by one of greater value. A horizontal bar over a letter increases its value 1000 times. 1918=1000 (M), +900 (CM), +18 (XVIII), or MCMXVIII Making Change. A girl buys meat for 42¢ and gives the cashier a two-dollar bill. How much change should she receive? "42 cents." The cashier will look at the sales slip and say, He will then count out 3 cents, a nickel, 2 quarters, and a dollar bill, saying, “45, 50, 75, $1, $2.” ORAL EXERCISE What change should be given for the amounts at the left if the following purchases are made? 1. $1.00 $.69 $ .87 $.29 $ .36 $ .16 $ .13 $.18 Add rapidly. Check by adding in the opposite direction. Keep a record of your time in each drill. |