THE YOUTH'S ASSISTANT IN THEORETIC AND PRACTICAL ARITHMETIC: DESIGNED FOR THE USE OF SCHOOLS GENERALLY BY ZADOCK THOMPSON, A. M. Stereotype Edition. BURLINGTON: H. JOHNSON & CO. 1839. The following explanations and table, not being contained in the Written Arithmetic, are inserted here for the convenience of those who have not studied Mental Arithmetic, Equality is expressed by two horizontal marks; thus 100 cts. I dollar, signifies that 100 cents are equal to one dollar. +Addition is denoted by a cross, formed by one horizontal and one perpendicular line, placed between the number; as 4+5 9, signifying that 4 added to 5 equals 9. XMultiplcation is denoted by a cross, formed by two oblique lines placed between the numbers: as 5×3=15, signifying that 5 multiplied by 3, or 3 times 5 are equal to 15. -Subtraction is denoted by one horizontal mark, placed between the numbers; as 7-4-3, signifying that 4 taken from 7 leave 3. (or Division is denoted three different ways; 1st by the reversed parenthesis; 2ndly, by a horizontal line placed between the numbers with a dot on each side of it; and 3dly, by. writing the number to be divided over the other in the form of a fraction; thus 2)6(3, and 6÷÷2=3 and §=3, all signify the same thing, namely, that if 6 be divided by 2 the quotient is 3, MULTIPLICATION AND DIVISION TABLE. 1 2 3 4 5 6 7 8 9 10 11 12 5 10 15 20 25 30 35 40 45 50 55 60 7 14 21 28 35 54 601 661 72 63 70| 77 84 8 16 24 32 40| 48| 56| 64| 72 80 88| 96 Entered according to Act of Congress, in the year one thousand eight hundred and twenty eight, by ZADOCK THOMPSON, in the Clerk's Office of the District of Vermont. HARVARD COLLEGE LIBRANY GIFT OF THE GRADUATE SCHOOL OF EDUCATION MAY 19 1926 |