iiiiiiiilii:l-J^^IN MEMORIAMFLORIAN CAJORIO^^X^i^J^^A. (Ay/^n.-^-nx^'tin CX C^U ^V-a*t.^X-^(./f^o-^Ciy^.il^APPLIED MATHEMATICSFORJUNIOR HIGH SCHOOLS;AND : .%,, ;; -^HIGH SCHO0tSji:V;i:-i^iBYEUGENE HENRY BARKERFORMBRLY HEAD OF THE DEPARTMENT OF MATHEMATICS IN THEPOLYTECHNIC HIGH LOS CALIFORNIASCHOOL, ANGELES,ALLYN AND BACONBOSTON NEW YORK CHICAGOATLANTA SAN FRANCISCOBYCOPYRIGHT, 1920.H. BARKEREUGENECAJORlNortoooti ^rcBBCo. Berwick & Smith Co.J. S. GushingU.S.A.Norwood, Mass.,PREFACE,has been written to meetThis book the demand for acourse in mathematics which shall coor-appliedpracticalschoolroom lesson and thedinate the actual ofproblemindustrial and commercial world. Itthe thepresentsof mathematical information which is to be ofbody likelymatter what one'sno be.service,daily occupation mayMathematics is the of twelveApplied outgrowth yearsin a ofof school over two thousandexperimentation highand the exercises in the book have stood thestudents,The andtest of classroom trial. haveexamples problemsbeen selected from fields industrial, commercial,manyas far as are suchmechanical, and,agricultural possible,as occur in the on the in thehousehold, farm, factory,inand at the office. The book teachable form:givesAn treatment of the fundamental opera-(1) adequatetions of with attention to modernarithmetic, propermethods of theseperforming operations.A consideration of business transactions.ordinary(2)A with the ofsufficient(3) ...
iiiiiiiilii:l-J^^
IN MEMORIAM
FLORIAN CAJORIO^^X^i^J^^A. (Ay
/^n.-^-nx^'tin CX C^U ^V-a*t.^X-^
(.
/f^o-^Ciy^.il^APPLIED MATHEMATICS
FOR
JUNIOR HIGH SCHOOLS
;AND : .%,, ;; -^
HIGH SCHO0tSji:V;i:-i^i
BY
EUGENE HENRY BARKER
FORMBRLY HEAD OF THE DEPARTMENT OF MATHEMATICS IN THE
POLYTECHNIC HIGH LOS CALIFORNIASCHOOL, ANGELES,
ALLYN AND BACON
BOSTON NEW YORK CHICAGO
ATLANTA SAN FRANCISCOBYCOPYRIGHT, 1920.
H. BARKEREUGENE
CAJORl
Nortoooti ^rcBB
Co. Berwick & Smith Co.J. S. Gushing
U.S.A.Norwood, Mass.,PREFACE
,
has been written to meetThis book the demand for a
course in mathematics which shall coor-appliedpractical
schoolroom lesson and thedinate the actual ofproblem
industrial and commercial world. Itthe thepresents
of mathematical information which is to be ofbody likely
matter what one'sno be.service,daily occupation may
Mathematics is the of twelveApplied outgrowth years
in a ofof school over two thousandexperimentation high
and the exercises in the book have stood thestudents,
The andtest of classroom trial. haveexamples problems
been selected from fields industrial, commercial,many
as far as are suchmechanical, and,agricultural possible,
as occur in the on the in thehousehold, farm, factory,
inand at the office. The book teachable form:gives
An treatment of the fundamental opera-(1) adequate
tions of with attention to modernarithmetic, proper
methods of theseperforming operations.
A consideration of business transactions.ordinary(2)
A with the ofsufficient(3) acquaintance symbols alge-
bra and of to enable the student tooperationsalgebraic
formulas.andinterpret apply simple
to enable him to the(4) computeEnough geometry
areas and of the commonvolumes geometric figures.
A of charts and their use.(5) study graphic
tables.in the use of mathematical(6) Training
Practice in the to a result(7) computedpower judge
with reference to its reasonableness.
iii
9il35IV PREFACE
drawn on various sources for thematerials,Having
author takes this to his indebtednessopportunity express
to numerous interested teachers and technical workers
whose criticisms and advice have been of invaluable serv-
ice in the of the book. does hepreparation Especially
desire to to his friend Dr. Na-acknowledge obligation
thaniel L. of the of forGardner, California,University
assistance andkindly sympathetic encouragement.
E. H. B.
San Francisco, California,
March, 1920.CONTENTS
PAGE
List of Illustrations and Maps vii
CHAPTER
I. Addition and Subtraction . . . . . . 1
II. Multiplication and Division 15
III. Fractions and Factors 34
IV. Decimals. Bills and Accounts 54
V. Percentage 69
VI. Denominate Numbers 93
VII. The ofUse Tables 124
VIII. Koot and Cube Root 135Square
IX. Mensuration . . 146
X. Graphical Representation 168
XI. Ratio and Proportion 180
XII. The Use of Formulas . 196
XIII. Agricultural Problems 202
XIV. Mechanical 213
XV. Miscellaneous Problems 226