# Dubbs' Complete Mental Arithmetic: A Volume of Carefully Graded Exercises Adapted to the Use of All Schools

American Book Company, 1893 - Arithmetic - 220 pages
"First edition of Dubbs' work on mental arithmetic. The author states in the preface that this subject is the most important that has been taught in the schools because it develops the reasoning faculties quicker than the study of any other discipline. The work consists of a series of problems in the various subjects of primary mathematics, including the basic sections, fractions, interest, discounts and percentages, among others. These are 'carefully graded exercises adapted to the use of all schools.' All to be accomplished without pencil or paper!" -- Antiquarian bookseller's description, 2018.

### Contents

 Addition I 3 Subtraction II 11 Addition and Subtraction 18 Multiplication 20 Division 28 Multiplication and Division 35 Principles 42 Factoring 44
 Tables 108 Questions 125 Percentage 163 Interest 190 Discount 201 Involution and Evolution 203 Miscellaneous Questions 209 Copyright

 Fractions 47

### Popular passages

Page 115 - SQUARE MEASURE 144 square inches (sq. in.) = 1 square foot (sq. ft.) 9 square feet — 1 square yard (sq. yd.) 30^ square yards = 1 square rod (sq. rd.) 160 square rods = 1 acre (A.) 640 acres = 1 square mile (sq.
Page 207 - The square of the sum of two numbers is equal to the square of the first, plus twice the product of the first by the second, plus the square of the second.
Page 109 - TABLE. 2 pints pt. make 1 quart, marked qt. 8 quarts - 1 peck, - pk. 4 pecks - 1 bushel, - bu.
Page 118 - Thirty days hath September, April, June, and November ; All the rest have thirty-one, Except the second month alone, Which has but twenty-eight, in fine, Till leap year gives it twenty-nine.
Page 201 - DISCOUNT. DISCOUNT is an allowance made for the payment of money before it is due. The present worth of a debt payable at...
Page 112 - LIQUID MEASURE 4 gills (gi.) = 1 pint (pt.) 2 pints — 1 quart (qt.) 4 quarts = 1 gallon (gal.) 31| gallons = 1 barrel (bbl.) 2 barrels = 1 hogshead (hhd...
Page 80 - Reduce the fractions to a common denominator and divide the numerator of the dividend by the numerator of the divisor.
Page 28 - Division is the process of finding how many times one number is contained in another ; or of finding one of the equal parts of a number.
Page 45 - A number is divisible by 3 if the sum of its digits is divisible by 3• A number is divisible by 9 if the sum of its digits is divisible by 9.